His daughter Sandy quotes Will Crowther as saying, “You know I've done all sorts of wonderful things in my career, it's funny that the one thing I'm remembered for is ‘Adventure’ ” [ Lawrence 2002 ]. Before he coded his legendary game, Crowther had helped map the complex network of caverns on which the game is based; and before that, he had already secured a place in history due to his contributions to a different network. As a member of the team of programmers at Bolt, Beranek and Newman (BBN), he helped create the ARPANET, the immediate forerunner to the internet.

Crowther has described himself putting a copy of the game on his BBN computer, leaving for a month's vacation, and returning to find the game being played all over the internet [ Hafner 1994 ]. Among those who found the game at this stage were two Stanford graduate students, Don Woods and John Gilbert. According to Gilbert (2005) , someone (possibly the instructor, Bob Floyd) mentioned the game in their CS204 class (a “programming and problem-solving seminar”) — after which Gilbert and Woods “stayed up all night at the AI lab playing the game and mapping the cave, including scanning the binary code for character strings in order to guess what the possibilities were.” After contacting Crowther and requesting the source code, Woods greatly increased the game's size, complexity, and polish. “In early 1977…. [w]henarrived at MIT, the reaction was typical: after everybody spent a lot of time doing nothing but solving the game (it's estimated thatset the entire computer industry back two weeks), the true lunatics began to think about how they could do it better” [ Anderson 1985 ]. During this time, Tom Van Vleck was a managing engineer at Honeywell. He describes “Adventure” as just another fad. “[S]ome staff members spent many hours at it. Others played it once or twice, showed it to relatives and friends, and lost interest. Gaming was not a source of interest in computing, or a way of recruiting people to the field: it was something we could do with the machine that was comprehensible to non-computer folks, who were often baffled about what a computer was and what we did” [ Van Vleck 2001 ]. But at MIT, a group of hackers was sufficiently captivated by “Adventure” that they developed a similar game, “Zork,” along with a company, Infocom, to market it [ Anderson 1985 ]; [ Briceno et al. 2000 ].

While BBN was actively researching artificial intelligence at the time Crowther was building “Adventure”, the game “was just some rather simplistic logic and a small table of known words — of course backed up by some very clever thinking,” according to Kraley (2004) , whose office was across from Crowther's. Kraley joined Crowther in a months-long Dungeons and Dragons campaign (led by Eric Roberts and including future Infocom co-founder Dave Lebling among the core of about eight participants). “[O]ne day, a few of us wandered into [Crowther's] office so he could show off his program. It was very crude in many respects — Will was always parsimonious of memory — but surprisingly sophisticated. We all had a blast playing it, offering suggestions, finding bugs, and so forth.” Crowther's original Adventure impressed his colleagues. “Will was very proud - or more accurately amused - of how well he could fool people into thinking that there was some very complex AI behind the game,” according to Kraley. Nevertheless, “once it was working, Will wasn't very interested in perfecting or expanding it.”

Crowther's prose was lean and condensed, as we see in item 3. The subject “DWARF” is followed by a tight array of six verbs, of which the first three (“WALKED,” “SAW” and “THREW”) pertain to the subject, the next (“MISSED”) pertains to the direct object (“AXE”), and the final two (“CURSED” and “RAN”) pertain to the subject. The compressed structure leads to an amusing ambiguity, suggesting that the axe not only missed, but also cursed and ran away.

This short table (24 items) includes descriptions of game states that represent lasting changes to the environment. For example, if the player drops the keys in a room, then every time the player returns to the room, a message will indicate the presence of the keys. Some of these table entries describe obstacles, and others describe room features. Exclamation points emphasize the importance of valuable items, threats, and unexpected consequences.

An examination of this table reveals several insights. Crowther's original version contains no vocabulary words to represent commands for saving a game, reporting the score, or taking inventory of possessions; all these elements were added by Woods. One of the most versatile objects in the Crowther/Woods collaboration, the bottle — which can be empty or full, and refilled with water or oil — exists in a greatly simplified form in the Crowther original. The word “BOTTL[E]” and the word “WATER” both have the number 1020, indicating that the container and its contents were treated by Crowther as the same object. There are table entries for “POUR” and “DRINK,” both of which will set a flag that indicates the bottle is empty; yet there are no commands for refilling the bottle. Since the last prop in this list is 1023, the numbering suggests Crowther added the bottle at a late stage in the game's development.

Item 1018 and item 1022 are both given as “KNIFE”, but only item 1018 is set up to accept the synonym “KNIVE[S]”. Note that “HEADL[AMP]” is given as a synonym for “LAMP,” reflecting the caving practice of keeping the hands free by mounting the light source on one's head. (Don Woods added the synonym “LANTE” and referred to the light source as a “LANTERN.”)

A second group of 35 items, numbered from 1001-1023 with some omissions and duplication, represents objects, including props that can be picked up (e.g. the keys and various treasures), scenery items that affect the player's motion (e.g. the rough stone steps and the fissure in the Hall of Mists), and adversaries (the snake and the dwarves).

While navigation by compass directions is perhaps one of the most recognizable features of the text-adventure genre, the compass directions seem to have been added relatively late to the vocabulary data table. Thus, dozens of names for locations from the initial above-ground sequence (“HOUSE”, “GATE”, “FORES[T]”) and words associated with a more linear navigation style (“FORWA[RD]”, “BACK”, “ENTER” and “EXIT”) are numbered 2-26, with synonyms such as “NULL” and “NOWHE[RE]” sharing numbers. Terms for the concepts “UP” and “DOWN” and several synonyms appear at numbers 29 and 30, respectively, while the four cardinal compass directions appear in numbers 43-46, and the diagonals at 60 and 62-64. William F. Mann, a caver who “helped a bit with the mapping of the Bedquilt area” depicted in the game, recalls playing “several versions of ADVENTURE as they were being developed” [ Mann 2003 ]. According to Mann, the game had always included compass directions; he suggests that the late appearance of the compass directions in the vocabulary table indicates that Crowther moved that feature from the code file to the data file at that stage of development. Further evidence that supports the assertion that compass directions were always an important way of navigating in the game is found in Table 6, in which items 10, 11 and 14 are displayed variously when the player is having trouble navigating. Each of these first suggests navigation by compass points, then via place names (e.g. item 10: “I AM UNSURE HOW YOU ARE FACING. USE COMPASS POINTS OR NEARBY OBJECTS.”).

The numbering identifies the typed commands “ENTER”, “DOOR” and “GATE” with a value of 3, marking them as synonyms. The last item in this section, numbered 70, is “BEDQU[ILT]”. Most of these words are the names of specific locations, but words for general motion (“BACK”, “RETUR[N]” and “RETRE[AT]”) are also on the list. [17] While Adventure lore commonly reports that Crowther created the game for his young daughters, the keyword table suggests Crowther also had adult players in mind. The last keyword is an expletive.

This long table (193 items) represents every word the game recognizes, though all input is truncated to the first 5 characters. The first group of 93 lines stores strings that the game recognizes as attempts to move. These are numbered from 2-70 with some omissions and many duplicates.

The line “3 11 48” will move the player from inside the building (3) to “YOU'RE IN DEBRIS ROOM” when the player types the keyword 48 — the famous magic word “XYZZY”. Likewise, “3 33 65” describes how the player moves from inside the building to “YOU'RE AT Y2” (room 33) after invoking the magic word “PLUGH” (65).

The table handles some special events very efficiently. For instance, the Table 3 [Map Data] line “3 79 5 14” defines what happens when the player is in room 3 (“YOU'RE INSIDE BUILDING”) and types “DOWNS” or “STREAM” — a reasonable request, but one that the game does not permit. The game prints out the strings from Table 1 marked with value 79, or “THE STREAM FLOWS OUT THROUGH A PAIR OF 1 FOOT DIAMETER SEWER / PIPES. IT WOULD BE ADVISABLE TO USE THE DOOR.” Since the game has refused the requested action, the player should not end this turn in room number 79 (which does not exist), but rather should stay in room 3. The Table 3 [Map Data] entry for value 79 is “79 3 1”, which we may translate as “When temporarily in fake room 79, move the player to room 3 if the player has entered vocabulary keyword group 1.” But there is no vocabulary keyword group 1; the vocabulary word groups start with a value of 2. Just as room 79 is a room the player cannot visit, vocabulary group 1 represents a keyword that the player can never type. The code is set up to respond to these values by delivering a customized rejection message and returning the player to the room where the turn started.

The line “3 1 3 11 32 44” represents several ways to get from room 3 (“YOU'RE INSIDE BUILDING”) to room 1 (“YOU'RE AT END OF ROAD AGAIN”). These include several words (“ENTER”, “DOOR” and “GATE”) that Table 4 lists with a value of 3; another set (“OUT”, “OUTSI”, “EXIT”, and “LEAVE”) with a value of 11; the word “OUTDO[ORS]” (which has a value of 32) and “WEST” and “W” (which we have already seen carry the value of 44).

Table 3 links map locations with vocabulary word groups. Experienced coders are invited to spelunk the FORTRAN source directly [ Crowther 1976 ]; those who are unfamiliar with the language may appreciate a brief guided tour on how this table handles player navigation. The line “1 2 2 44”, when interpreted by the code, means “When in room 1 (‘YOU'RE AT END OF ROAD AGAIN’), print out the strings in Table 1 marked with value 2 ('YOU HAVE WALKED UP A HILL, STILL IN THE FOREST / THE ROAD NOW SLOPES BACK DOWN THE OTHER SIDE OF THE HILL. / THERE IS A BUILDING IN THE DISTANCE.') in response to the player typing keyword 2 (‘ROAD’) or a keyword from group 44 (‘WEST’ or ‘W’). Then, move the player to room 2, ‘HILL IN ROAD’.”

Table 2 holds 27 one-line items, numbered from 1-68, with many gaps. The entries in Table 1 that report failed attempts to move to the requested location, such as items 20-23 above, have no corresponding labels in Table 2. Rooms with short descriptions, such as #29 (“YOU ARE IN THE SOUTH SIDE CHAMBER.”) and most maze locations, also have no corresponding Table 2 entry.

The first line in the data file is not the first text displayed when the game starts, or the first instruction executed by the computer; rather, it is simply the first row in a table that stores long descriptions of game locations. Its 149 lines present 78 separate items numbered from 1-79 (omitting number 26). Items 42-58 include ten locations with the identical description “YOU ARE IN A MAZE OF TWISTY LITTLE PASSAGES, ALL ALIKE,” representing locations in a challenging three-dimensional maze. (Woods added a separate maze, with rooms that are “ALL DIFFERENT.”) Typically, the items in this table are displayed when the player has changed location, but some describe an unexpected game state.

The earliest source code for Crowther's PDP-10 “Adventure” game [ Crowther 1976 ], exists in two FORTRAN files — one for data, and one for code, dated 11 Mar 1977. According to Woods (2007) , these files show the program as Crowther left it, before Woods began debugging and expanding the code. The data file comprises six separate tables that contain most of the game's text: 1) long descriptions, 2) short room labels, 3) map data, 4) grouped vocabulary keywords, 5) static game states, and 6) hints and events. Embedded in the code file are the static components of variable strings, such as “ I SEE NO ‘,A5,’ HERE.” (where “A5” represents the name of an object). All text was written in all-caps due to the limitations of the PDP-10.

Notes on the Woods Expansion

Mann's assessment of the Crowther/Woods collaboration offers an apt summary: “Crowther was interested in using the cave as a setting for a game, with magic, puzzles, conflict, and humor. Woods carried that forward, but without the feel for being in an actual cave, and with a need to limit the use of the machine to off hours. He added mostly policy, puzzles and humor” [ Mann 2004 ]. Crowther supplied the original text-parser and established the basic principles of gameplay, leaving Woods free to concentrate on expansion, creative variation, and real-world resource management (such as a system for resuming a suspended game and a password-protected method of restricting access to the game during working hours). Woods retained the general structure of the code when he expanded the game, typically adding on to the end of the existing tables, and squeezing creative variations out of his own imagination and out of possibilities he found in Crowther's original material. For example, Crowther's original responds to the command “BLAST” with the message “BLASTING REQUIRES DYNAMITE,” but none exists in his game. Woods, however, incorporates “BLAST” into the finale.

Woods added several rooms to Crowther's existing “ALL ALIKE” maze (making the maze more challenging to navigate), and created his own maze, where the passages were “ALL DIFFERENT.” He also created a randomly-moving pirate who steals the player's treasures. Crowther supplied the humorous solution to the snake obstacle, but when the player tries to unleash the same feathered fury on Woods’s dragon, the results are comically disastrous. While Crowther's bottle of water can only be emptied, Woods adds complexity by making it refillable and capable of carrying water or oil. Woods also supplied puzzles for Crowther's consumable items (the food and the water). In a variation on the crystal bridge that can appear, Woods adds a bridge that can collapse.

Where Crowther was an efficient minimalist, Woods was comparatively lavish with scenery. Crowther did not create corpse objects for vanquished opponents; once defeated, the snake and the dwarves simply vanish. Woods, on the other hand, implements separate functional and destroyed objects for the dragon, the bear, and the troll bridge. He also created a plant that exists in three states – thirsty and small, thirsty and large, and sated and climbable. Because Woods added objects with complex behavior, his code had to deal with an even greater number of potential events. (For example, what happens when a wandering dwarf encounters the bear or the dragon?)

Woods edited for standard usage, and occasionally for clarity. Upon starting “Adventure”, the player's first choice is whether to ask for instructions (see Example 1 , below).

Crowther, 1975-76 1 SOMEWHERE NEARBY IS COLOSSAL CAVE, WHERE OTHERS HAVE FOUND

1 FORTUNES IN TREASURE AND GOLD, THOUGH IT IS RUMORED

1 THAT SOME WHO ENTER ARE NEVER SEEN AGAIN. MAGIC IS SAID

1 TO WORK IN THE CAVE. I WILL BE YOUR EYES AND HANDS. DIRECT

1 ME WITH COMMANDS OF 1 OR 2 WORDS.

1 (ERRORS, SUGGESTIONS, COMPLAINTS TO CROWTHER)

1 (IF STUCK TYPE HELP FOR SOME HINTS) Crowther and Woods, 1977 1 SOMEWHERE NEARBY IS COLOSSAL CAVE, WHERE OTHERS HAVE FOUND FORTUNES IN

1 TREASURE AND GOLD, THOUGH IT IS RUMORED THAT SOME WHO ENTER ARE NEVER

1 SEEN AGAIN. MAGIC IS SAID TO WORK IN THE CAVE. I WILL BE YOUR EYES

1 AND HANDS. DIRECT ME WITH COMMANDS OF 1 OR 2 WORDS. I SHOULD WARN

1 YOU THAT I LOOK AT ONLY THE FIRST FIVE LETTERS OF EACH WORD, SO YOU'LL

1 HAVE TO ENTER “NORTHEAST” AS “NE” TO DISTINGUISH IT FROM “NORTH”.

1 (SHOULD YOU GET STUCK, TYPE “HELP” FOR SOME GENERAL HINTS. FOR INFOR-

1 MATION ON HOW TO END YOUR ADVENTURE, ETC., TYPE “INFO”.)

1 - - -

1 THIS PROGRAM WAS ORIGINALLY DEVELOPED BY WILLIE CROWTHER. MOST OF THE

1 FEATURES OF THE CURRENT PROGRAM WERE ADDED BY DON WOODS (DON @ SU-AI).

1 CONTACT DON IF YOU HAVE ANY QUESTIONS, COMMENTS, ETC.

Woods retained the purely aesthetic portion of Crowther's instructions (offering a motivation for the player's actions and introducing the fantasy element), but added details pertaining to the text parser, session mechanics, and authorship. While Crowther ended his instructions with a no-nonsense, “IF STUCK TYPE HELP FOR HINTS,” Woods expanded, qualified, and punctuated the statement thus: “SHOULD YOU GET STUCK, TYPE ‘HELP’ FOR SOME GENERAL HINTS”. Woods also added a note about the parser's inability to tell the difference between “NORTH” and “NORTHEAST,” illustrating the attention he paid to improving the playing experience.

Both versions offer hints accessible by typing “HELP” (see Example 2 , below). To Crowther's original “HELP” text, Woods added a reference to the new verb “INVENTORY,” and clarified a passage referring to manipulating objects.

Crowther, 1975-76 51 I KNOW OF PLACES, ACTIONS, AND THINGS. MOST OF MY VOCABULARY

51 DESCRIBES PLACES AND IS USED TO MOVE YOU THERE. TO MOVE TRY

51 WORDS LIKE FOREST, BUILDING, DOWNSTREAM, ENTER, EAST, WEST

51 NORTH, SOUTH, UP, OR DOWN. I KNOW ABOUT A FEW SPECIAL OBJECTS,

51 LIKE A BLACK ROD HIDDEN IN THE CAVE. THESE OBJECTS CAN BE

51 MANIPULATED USING ONE OF THE ACTION WORDS THAT I KNOW. USUALLY

51 YOU WILL NEED TO GIVE BOTH THE OBJECT AND ACTION WORDS

51 (IN EITHER ORDER), BUT SOMETIMES I CAN INFER THE OBJECT FROM

51 THE VERB ALONE. THE OBJECTS HAVE SIDE EFFECTS - FOR

51 INSTANCE, THE ROD SCARES THE BIRD.

51 USUALLY PEOPLE HAVING TROUBLE MOVING JUST NEED TO TRY A FEW

51 MORE WORDS. USUALLY PEOPLE TRYING TO MANIPULATE AN

51 OBJECT ARE ATTEMPTING SOMETHING BEYOND THEIR (OR MY!)

51 CAPABILITIES AND SHOULD TRY A COMPLETELY DIFFERENT TACK.

51 TO SPEED THE GAME YOU CAN SOMETIMES MOVE LONG DISTANCES

51 WITH A SINGLE WORD. FOR EXAMPLE, “BUILDING” USUALLY GETS

51 YOU TO THE BUILDING FROM ANYWHERE ABOVE GROUND EXCEPT WHEN

51 LOST IN THE FOREST. ALSO, NOTE THAT CAVE PASSAGES TURN A

51 LOT, AND THAT LEAVING A ROOM TO THE NORTH DOES NOT GUARANTEE

51 ENTERING THE NEXT FROM THE SOUTH. GOOD LUCK! Crowther and Woods, 1977 51 I KNOW OF PLACES, ACTIONS, AND THINGS. MOST OF MY VOCABULARY

51 DESCRIBES PLACES AND IS USED TO MOVE YOU THERE. TO MOVE, TRY WORDS

51 LIKE FOREST, BUILDING, DOWNSTREAM, ENTER, EAST, WEST, NORTH, SOUTH,

51 UP, OR DOWN. I KNOW ABOUT A FEW SPECIAL OBJECTS, LIKE A BLACK ROD

51 HIDDEN IN THE CAVE. THESE OBJECTS CAN BE MANIPULATED USING SOME OF

51 THE ACTION WORDS THAT I KNOW. USUALLY YOU WILL NEED TO GIVE BOTH THE

51 OBJECT AND ACTION WORDS (IN EITHER ORDER), BUT SOMETIMES I CAN INFER

51 THE OBJECT FROM THE VERB ALONE. SOME OBJECTS ALSO IMPLY VERBS; IN

51 PARTICULAR, “INVENTORY” IMPLIES “TAKE INVENTORY”, WHICH CAUSES ME TO

51 GIVE YOU A LIST OF WHAT YOU'RE CARRYING. THE OBJECTS HAVE SIDE

51 EFFECTS; FOR INSTANCE, THE ROD SCARES THE BIRD. USUALLY PEOPLE HAVING

51 TROUBLE MOVING JUST NEED TO TRY A FEW MORE WORDS. USUALLY PEOPLE

51 TRYING UNSUCCESSFULLY TO MANIPULATE AN OBJECT ARE ATTEMPTING SOMETHING

51 BEYOND THEIR (OR MY!) CAPABILITIES AND SHOULD TRY A COMPLETELY

51 DIFFERENT TACK. TO SPEED THE GAME YOU CAN SOMETIMES MOVE LONG

51 DISTANCES WITH A SINGLE WORD. FOR EXAMPLE, “BUILDING” USUALLY GETS

51 YOU TO THE BUILDING FROM ANYWHERE ABOVE GROUND EXCEPT WHEN LOST IN THE

51 FOREST. ALSO, NOTE THAT CAVE PASSAGES TURN A LOT, AND THAT LEAVING A

51 ROOM TO THE NORTH DOES NOT GUARANTEE ENTERING THE NEXT FROM THE SOUTH.

51 GOOD LUCK!

Crowther had written “USUALLY PEOPLE TRYING TO MANIPULATE AN OBJECT ARE ATTEMPTING SOMETHING BEYOND THEIR (OR MY!) CAPABILITIES…” Because players see this passage only after typing “HELP,” the context suggests that this passage refers to a player having difficulty manipulating an object; yet a novice player who encounters that passage very early in the game might conclude that the game does not permit any manipulation at all. Woods's revision refers more precisely to “TRYING UNSUCCESSFULLY TO MANIPULATE AN OBJECT” (emphasis added). Likewise, where Crowther referred to manipulating objects using “ONE OF THE ACTION WORDS THAT I KNOW”, Woods avoided giving the impression that an object can be manipulated with only one action word, so that his passage refers instead to “ SOME OF THE ACTION WORDS” (emphasis added).

While the player is informed that the chamber is “splendid,” the text does not explicitly state what emotional effect the height of the chamber or the proximity of the “frozen rivers of orange stone” is supposed to have. Rather, we see this location through seasoned, critical eyes, duly noting the presence of geological wonders, but then immediately evaluating the next possible move, as one must do when exploring in a real cave. As it happens, the “awkward” exit from the Orange River Room is the way back to the surface, and the “good passage” leads deeper into the cave. Without clumsily announcing something like, “The west exit looks so intriguing that you can hardly wait to explore it,” the text subtly discourages the player's premature exit, and reinforces the exploratory premise of classic text adventures. [Jerz and Thomas 2005] Crowther's potent writing features in Room 13, “…A SPLENDID CHAMBER THIRTY FEET HIGH. THE WALLS ARE FROZEN RIVERS OF ORANGE STONE. AN AWKWARD CANYON AND A GOOD PASSAGE EXIT FROM EAST AND WEST SIDES OF THE CHAMBER.” A forthcoming study of caves as computer game environments assesses this passage as follows:

“Adventure” succeeds in large part due to the depth and realism of the scenery, which is rendered in concise prose that calls interesting details to the reader's attention, yet leaves much to the imagination. The “Breath-Taking View” ( Crowther and Woods, Room 126 ) is an exception; co-authored by Gilbert, the graduate student who played Crowther's version of “Adventure” with Woods late into the night, its effusive language not only tells what the room looks like, but also informs the reader what emotions the scene is supposed to invoke (cf. the gorge “FILLED WITH A BIZARRE CHAOS OF TORTURED ROCK WHICH SEEMS TO HAVE BEEN CRAFTED BY THE DEVIL HIMSELF”). When Nelson analyzes the tension between Crowther's austere fantasy vision and the often comical set pieces supplied by Woods, he finds the stylistic conflict an agreeable part of the game's charm. “Stretching a point, you could say that there is a Crowther and a Woods in every designer, the one intent on recreating an experienced world, the other with a really neat puzzle which ought to fit somewhere ” [ Nelson 2001 , 345]. Notable tension is evident in changes to the cave environment that occur in the Woods expansion, such as 1) the underground volcano, 2) the battery-dispensing vending machine, and 3) announcements from a public address system warning that the cave is closing. Lacking firsthand experience of caves, Woods had to rely upon his own imagination. Yet even these details logically extend, respectively, Crowther's use of 1) intriguing geography, 2) treasure items, and 3) magic words. Some of Woods's additions, such as the Soft Room and the Oriental Room, seem completely out of place when considered separately; but once it becomes clear that objects found in these two locations work together to solve an inventory puzzle, these two incongruities make perfect sense as gaming elements.

In 1994, Crowther reflected on the success of the game: “And why did people enjoy it? Because it's exactly the kind of thing that computer programmers do. They're struggling with an obstinate system that can do what you want but only if you can figure out the right thing to say to it” [ Hafner 1994 , 2–3]. Crowther's children both recall instances in which their father deflected their frustration with “Adventure” by noting that they were stuck on one of Woods’s details (see Section 4 ). According to Crowther (2001) , “My intent was that the deeper you went into the cave, the more fantasy appeared. Don made it appear faster than ever I would have, which in retrospect was good”.

Woods's most striking diversions from Crowther's initial realism occur on the far side of the troll bridge, yet this region is only accessible after the player has encountered Crowther's earlier scenery, which involves capturing a strangely passive little bird, watching the improbable defeat of a fierce snake, conjuring up a magical crystal bridge, teleporting via magic words, and fighting with dwarves whose corpses vanish. Given this context, the fairy-tale elements that Woods supplied (including a dragon, a troll, a beanstalk, more magic words, and a friendly bear) seem perfectly in keeping with Crowther's fantasy premise.