When using source material, the Coen brothers seem to take two different approaches. They either render the material as faithfully as cinematically possible (True Grit; No Country for Old Men), or they adapt the material to extents unrecognizable beyond loose allusions. O Brother, Where Art Thou?, which contains a number of occasional narrative details shared with Homer’s Odyssey, is probably the best known of this latter approach. Lesser known is The Big Lebowski’s debt to Raymond Chandler’s The Big Sleep. Though the connection between the Dude and Philip Marlowe goes far beyond the word Big in both titles, no one could convincingly call The Big Lebowski a faithful rendition of The Big Sleep.

The Coen brothers’ newest addition, Inside Llewyn Davis, is purportedly based on the life of Dave Van Ronk, as told in his autobiography, The Mayor of MacDougal Street. Now, the movie does contain a folk singer as its protagonist (Llewyn Davis, played by Oscar Isaac), and it is set in Greenwich Village in the early 1960s, but it certainly does not seem to be a movie, at least at its core, about the folk scene in 1960s New York. I haven’t read Van Ronk’s autobiography and don’t know much about really any of the scenes in New York, but I think it’s safe to say that Inside Llewyn Davis owes very little to The Mayor of MacDougal Street.

In fact, the Coen brothers have borrowed a number of allusions from another literary source which, despite its vast distance in historical setting, is much closer to the major themes of Inside Llewyn Davis. That source is Virgil’s Aeneid, which describes the wanderings of Aeneas made homeless by the Trojan War until he eventually settles (with much bloodshed) in Italy. Of course, the Aeneid only provides the Coen brothers with literary allusions and some narrative parallels. But what they do borrow effectively strengthens the essence of the film, and helps lead it out of its Greenwich setting into the timelessness of a folk song. As Llewyn himself says in the first non-sung words of the film, “If it was never new, and it never gets old, then it’s a folk song”. The same could be applied to the film itself, especially considering its literary relationship with Virgil’s never new and never old poem, the Aeneid.

Despite the great difference between the Aeneid and Inside Llewyn Davis, there are some clues provided that help make the identification. Most notably, is Llewyn’s journey to The Gate of Horn, a reference to the actual Chicago club of folk music fame, but also to one of the two gates of the underworld described in the Aeneid by which dreams (and Aeneas) enter the world. In the Aeneid true dreams pass through the Gate of Horn, whereas false dreams (and Aeneas) pass through the Gate of Ivory. I think it must be significant that the scenes just preceding Llewyn’s performance at The Gate of Horn are the most surreal and dreamlike of the movie. For one, Roland Turner (played by John Goodman) is constantly sleeping (for reasons that are later explained in the film).

A later allusion provides a second concrete key to the source. The cat of the film, Llewyn’s occasional fellow wanderer and feline mirror, happens to be named Ulysses, the Greek hero who in own his wanderings and search for home is Virgil’s mirror for Aeneas (Ulysses is the name used for Odysseus in the Aeneid). In the film, it must be significant that Llewyn expresses surprise, even shock, upon hearing the cat’s name. Thematically, this is important, for at that moment, Llewyn seems to recognize his existential connection to the home-searching cat through the literary allusion to its name. This recognition is further supported immediately afterwards, when Llewyn comes across a poster of The Incredible Journey, a Disney movie about three pets wandering through the Canadian wilderness to find their way back home. Again, he stares at it ponderously, perhaps putting the two references together in a moment of epiphany.

With these two concrete allusions (The Gate of Horn and Ulysses) pointing the way, others can be teased out. Jean (played by Carey Mulligan) is an obvious Dido, scorned and angry at the hero for potentially impregnating her—an inversion of the Aeneid where Dido desires to become impregnated by Aeneas, but shows equal, if not more, scorn when he abandons her.

Moreover, the way to Chicago seems to parallel Aeneas’ trip into the underworld, with the driver Johnny Five (played by Garrett Hedlund) as a kind of Charon, silently steering his vessel, and Roland Turner as a kind of demonic Rhadamanthus, ever so judging and, as he claims, practiced in the dark arts. (I’ll note that Goodman played the Devil, or at least a Devil-like, character in the earlier Coen brothers’ film, Barton Fink). On this trip, Llewyn also has to pay for gas, much like Aeneas must pay for his ferry ride.

And at the end of Inside Llewyn Davis (possible spoiler alert ahead), the man who attacks Llewyn simply vanishes into the darkness of New York. The Aeneid ends similarly: in the final line of the poem, Aeneas’ foe, Turnus, is killed and his soul flies off into the “shadows”.

There are other allusions that can be teased out, but to conclude, I will provide only one more. While in a restroom stall, Llewyn looks over at graffiti on the wall, which reads: “What are you doing?” Ignoring the obvious implications of the toilet humour, Llewyn’s confused (again almost shocked) expression points to the deeper meaning of the message, as if it was speaking directly to him, questioning his decisions to wander homeless from couch to couch, from trivial gig to gig. In what must be its literary source, the Aeneid describes Mercury coming to Aeneas, who is wasting his life away in Carthage, in order to shake him back on his journey to find a home. Like Llewyn’s restroom graffiti, Mercury twice inquires of Aeneas, according to Rolfe Humphries’ well-known translation, “What are you doing?” (p. 96).

It is this question, asked of both Llewyn and Aeneas, that strikes at the hearts of the homeless wanderers, attempting to stir them onward and homeward. A fitting theme for a folk song.