After a two-year hiatus, the BBC's Sherlock is back, reuniting stars Benedict Cumberbatch and Martin Freeman. Created by Mark Gatiss and Steven Moffat, the show premiered in 2010, modernizing the original stories by Sir Arthur Conan Doyle of his consulting detective Sherlock Holmes and military veteran Dr. John Watson. After the online mini-episode "Many Happy Returns," the season 3 premiere "The Empty Hearse," which aired in America last night, features the hero returning to London after faking his death in "The Reichenbach Fall."

Like many of the show's episodes, the premiere was packed full of references to Arthur Conan Doyle's many Sherlock Holmes stories – and even a few for Doctor Who. Read on for all the clever shout-outs and references you might have missed.

WHAT WE SEE: The title of this episode is "The Empty Hearse."

WHAT IT MEANS: The name references Doyle's story "The Adventure of the Empty House," which revived Sherlock three years after his apparent death at the Reichenbach Falls in the story "The Final Problem." This episode takes place two years after the television show's Season 2 finale "The Reichenbach Fall," which also ended with the apparent death of Sherlock.

WHAT WE SEE: In Mycroft's office, he mentions that Sherlock stopped the "colossal" scheme of Baron Maupertius, the last of Moriarty's agents.

WHAT IT MEANS: In Doyle's story "The Adventure of the Reigate Squire," Watson mentions a publicized and difficult case Holmes solved concerning the "the colossal schemes of Baron Maupertius," but then remarks that it's too political to fully share with his readers.

WHAT WE SEE: Sherlock surprises Watson by disguising himself as French waiter and then announcing himself. John almost faints from the shock. Sherlock later apologizes for thinking his reveal would be fun.

WHAT IT MEANS: Doyle's "The Greek Interpreter" revealed Holmes had French heritage. In "The Empty House," he visited Watson disguised as an old bookseller before revealing his true identity, causing Watson to faint. In Doyle's stories, Holmes sometimes apologized that he couldn't resist dramatic reveals.

WHAT WE SEE: John proposes to Mary Morstan, his girlfriend of six months, played by Martin Freeman's real-life partner Amanda Abbington.

WHAT IT MEANS: In the second Sherlock Holmes story published, "The Sign of Four," Mary Morstan was a client of Holmes. By the end of the story, Watson and Mary had fallen in love and were engaged.

WHAT WE SEE: While explaining his survival to John, Sherlock mentions that his second escape plan involved "a system of Japanese wrestling."

WHAT IT MEANS: In "The Empty House," Holmes says he defeated Moriarty thanks to his knowledge of "baritsu, or the Japanese system of wrestling." This was a misspelling of Bartitsu, a martial art popular during Doyle's time, but it has become an often-referenced thing among fans. Comic book characters Doc Savage and the Shadow have both been said to be masters of "baritsu."

WHAT WE SEE: Sherlock examines Mary and concludes: "only child," "shortsighted," "part time nurse," "guardian," "clever," "linguist," liar," "romantic," "disillusioned Lib Dem," "Size 12," "cat lover," "appendix scar," "bakes own bread," "secret tattoo."

WHAT IT MEANS: In Doyle's story "The Sign of Four," Mary Morstan was indeed an only child and a romantic; she and Watson fell in love at first sight. "Guardian" may allude to her originally working as a governess in Doyle's story or the general role she assumes with others. "Clever" would be in keeping "The Sign of Four," where Holmes remarked that she was "a model client," possessing intelligence and "the correct intuition, " while Watson noted she had a refined, sensitive nature coupled with remarkable poise and self-control. We see later in this episode that she is a part-time nurse at John's practice.

WHAT WE SEE: Sherlock greets Inspector Lestrade as "Graham" and is then corrected that the man's name is "Greg."

WHAT IT MEANS: Lestrade frequently appeared in Doyle's stories, though his first name wasn't given, only the initial G.

WHAT WE SEE: During the meeting of the Empty Hearse group, a television news report announces that Sherlock Holmes has been seen alive. At the bottom of the screen, a ticker reads: "Magnussen summoned before Parliamentary commission."

WHAT IT MEANS: This is the first mention of Charles Augustus Magnussen, who will appear briefly in this episode and then be mentioned again in "The Sign of Three," before his full introduction in "His Last Vow."

__WHAT WE SEE: __ The news media refers to Sherlock as the "Hat Detective."

WHAT IT MEANS: In the season 2 episode "A Scandal in Belgravia," Sherlock tried to hide his face from photographers by throwing on a deerstalker cap. This lead to a headline referring to him and John as "Hat-Man and Robin."

WHAT WE SEE: Mary is reading one of John's blogs about his adventures with Sherlock on a tablet. This is areal website that went up starting with the first season.

WHAT IT MEANS: The passage Mary is reading is actually a direct excerpt from the original Doyle story "The Sign of Four," which introduced her character.

WHAT WE SEE: In his apartment alone, Sherlock muses that London is a "great cesspool into which all kinds of criminals, agents and drifters are irresistibly drained."

WHAT IT MEANS: This is a reference to Watson's description of London in the very first story "A Study in Scarlet," where he calls it "that great cesspool into which all the loungers and idlers of the Empire are irresistibly drained."

WHAT WE SEE: Sherlock dispatches members of his homeless network to spy on people he's deemed to be "markers" and "rats."

WHAT IT MEANS: In Doyle's story "A Study in Scarlet," Holmes revealed that he occasionally relied on a group of homeless children to act as his eyes and ears. These children were known as the Baker Street Irregulars.

WHAT WE SEE: Mycroft remarks that he is "the smart one" of the family and Sherlock recalls how he used to think he was an idiot before he met other children.

WHAT IT MEANS: In Doyle's stories, Sherlock told Watson very plainly that his older brother was indeed smarter. He added that he sometimes went to Mycroft for advice when he couldn't solve a case and that "what is to me a means of livelihood is to him the merest hobby of a dilettante."

WHAT WE SEE: Sherlock notices a hat left behind by a client while he was out and challenges Mycroft to deduce what kind of person wore it.

WHAT IT MEANS: This is a double reference. In Doyle's "The Blue Carbuncle," Holmes came home to find a hat left by a client who'd missed him, then used it to figure out who had stopped by. When Mycroft was introduced in "The Greek Interpreter," he and Holmes immediately played a familiar game where they looked at a stranger on the street and concluded everything they could about them.

WHAT WE SEE: Sherlock suggests the size of the hat means it's a man's and Mycroft points out that this is a silly conclusion.

WHAT IT MEANS: In "The Blue Carbuncle," Holmes remarks that the owner of the hat he found must be intelligent based on the size of the head. This has often been criticized by fans and is sometimes taken as a joke rather than a serious conclusion.

WHAT WE SEE: With Molly at his side, Sherlock remarks on a case involving monkey glands and Professor Presbury. He also concludes that Mr. Windibank secretly became his own stepdaughter's online boyfriend for financial gain.

WHAT IT MEANS: Monkey glands and Prof. Presbury are references to Doyle's story "The Adventure of the Creeping Man." The case of Mr. Windibank is an adaptation of "A Case of Identity," where a stepfather developed a relationship with his stepdaughter under a false identity, primarily via typewritten letters.

WHAT WE SEE: John meets with an elderly patient whose usual doctor is Dr. Verner. The patient then offers Dr. Watson some adult films and is wrongly accused of being Sherlock in disguise.

WHAT IT MEANS: In the Doyle story "The Empty House," Sherlock first revealed his survival to Watson by disguising himself as an elderly man offering to sell used books, which had the exact same titles as the adult films in this scene. Dr. Verner was Sherlock's cousin, mentioned in Doyle's story "The Adventure of the Norwood Builder," who bought Dr. Watson's practice soon after Holmes' apparent return from death so that John could become the detective's roommate and full-time partner again.

WHAT WE SEE: Sherlock and Molly enter the apartment of Howard Shilcott. His private study has a wall decorated by overlapping gears.

WHAT IT MEANS: Mark Gatiss and Steven Moffat have often slipped Doctor Who references into Sherlock. Shilcott's wall is remarkably similar to how the Doctor decorated his office in "The Invasion of Time" (1978), when he temporarily became President of the Time Lords.

WHAT WE SEE: Sherlock tells Molly that he was only able to defeat Moriarty because the villain overlooked her importance, saying, "Moriarty slipped up, he made a mistake."

WHAT IT MEANS: In "The Final Problem," Holmes said he was able to finally bring evidence against Moriarty and his organization because the villain made one fatal "slip," but he never explained what it was.

WHAT WE SEE: Sherlock remarks that not everyone Molly has a crush on can be a sociopath.

WHAT IT MEANS: Along with her longtime affection for Sherlock, Molly dated James Moriarty briefly in the season 1 episode "The Great Game," not realizing his true nature and agenda.

WHAT WE SEE: Mary gets a text about her husband, opening with the line "John or James Watson." The first word and each third word of the text turn out to be a secret message communicated through a "skip code."

WHAT IT MEANS: In Doyle's "The Adventure of the Gloria Scott," Holmes encountered a code involving every third word of a message. Also, Doyle occasionally mixed up character names or forgot them. In his story "The Man with the Twisted Lip," Mary called Watson "James" rather than John. To explain this, many fans decided that Watson's middle initial "H" stood for Hamish, a variant of James.

WHAT WE SEE: Sherlock approves of Watson getting rid of the mustache, saying, "I prefer my doctors clean-shaven."

WHAT IT MEANS: It's possible this is a joking jab from episode writer Mark Gatiss to follow writer and Sherlock co-creator Steven Moffat. In 2013, Moffat introduced the only incarnation of titular hero of Doctor Who to have facial hair, played by John Hurt.

WHAT WE SEE: John pays Sherlock a visit and the detective shoves his parents out the door.

WHAT IT MEANS: Sherlock's parents are played by Benedict Cumberbatch's own parents, Timothy Carlton and Wanda Ventham. Both are actors.

WHAT WE SEE: Sherlock tells John that the man who mysteriously vanished from a train is Lord Moran.

WHAT IT MEANS: In Doyle's "The Empty House," Lord Sebastian Moran was Moriarty's last active agent and used a specialized air-pressure rifle to murder people from afar.

WHAT WE SEE: Sherlock realizes that Moran's carriage detached from the train he was on and hid in an unused station.

WHAT IT MEANS: Sir Arthur Conan Doyle wrote a story "The Lost Special" that featured a train missing from a railway, later revealed to be hidden in an unused and unknown section.

WHAT WE SEE: The unused station hiding the train carriage is at Sumatra Road.

WHAT IT MEANS: In Doyle's story "The Sussex Vampire," Holmes referred to a case involving "the giant rat of Sumatra," then added that this was a story the world wasn't ready to hear. The throwaway line has inspired many storytellers over the years to explain it. Sherlock refers to Lord Moran in this episode as the "big rat" and "rat #1," so it's fitting that the villain's plans involve Sumatra Road.

WHAT WE SEE: Believing that they're about to die, John tells Sherlock that he is "the best and the wisest man that I have ever known."

WHAT IT MEANS: The very last line of Doyle's "The Final Problem," the story where Sherlock seemingly died, was Watson's narration saying that Sherlock Holmes was "the best and the wisest man whom I have ever known."

WHAT WE SEE: Sherlock explains his survival to Philip Anderson, who then criticizes that the explanation is not very impressive and concludes that the detective is lying.

WHAT IT MEANS: When Doyle later revealed how Sherlock had actually survived his "death," critics complained that the explanation was disappointing. Others suggested that the explanation was a lie by Holmes, and that the true story of his survival was more complicated. The explanation Sherlock provides here is nearly identical to a popular online explanation that circulated among fans starting the day after "The Reichenbach Fall" aired. Anderson may symbolize Sherlock viewers who will not find any explanation beyond their own to be satisfactory.

WHAT WE SEE: Concerning his survival, Sherlock tells Watson, "you know my methods." Watson then mentions visiting his grave and asking him to not be dead. Sherlock says he heard and implies this is how he came back.

WHAT IT MEANS: Some fans of Doyle's stories have enjoyed the possibility that Sherlock Holmes actually did die in "The Final Problem" and was literally resurrected years later. Many stories have used this premise, involving supernatural or angelic forces that return Holmes to life.

Alan Sizzler Kistler (@SizzlerKistler) is a writer/actor and the author of Doctor Who: A History.