- Geoffrey Firmin (Albert Finney) is the drunk you desperately try to avoid at parties. He's perpetually pickled, customarily stumbling about and slurring his words, all the while imagining that everyone is interested in what he's loudly saying. He arrives in the film tuxedoed, sunglassed, and hungover, having at some point in the past lost both his socks and car, presumably in different incidents. We find out that Geoffrey was until recently the British consul to this small Mexican town, but his current state is such that it is difficult to imagine him gainfully employed. To add even more flavor to this already interesting situation, we first encounter Geoffrey on the Mexican Day of the Dead just on the eve of World War II.
- After a full day of debauchery, Geoffrey finds that his barely remembered prayers have been answered when his estranged wife Yvonne (Jacqueline Bisset) returns from New York. As Geoffrey quickly reminds her, Yvonne's original departure stemmed from the affair she had with Geoffrey's half-brother Hugh (Anthony Andrews), who is investigating the rise of fascism in rural Mexico. This act of recollection spurs another of Geoffrey's drunken interludes, this one incorporating a memorable mid-road nap, but eventually the three of them are reunited at last. After an amusing attempt to sober Geoffrey up, they embark on a day trip out into the country.
- As they travel, the differences between Geoffrey and Hugh become more and more obvious. Hugh is an idealist who regrets running away from the Spanish Civil War. He's very much alive, playing an impromptu guitar song at a roadside bar and freely jumping into a nearby bullfighting ring. Geoffrey, on the other hand, is more of an animated corpse similar to those shown dancing in the film's opening credits. Just when it seems like he's reconciled with Yvonne, he insists on spoiling the moment by rehashing her infidelity. Although he has the choice to start his life anew, he memorably chooses the opposite, claiming that hell is his "natural habitat." The rest of the film depicts the exact route he takes to get there.
- Finney's performance is nothing short of spectacular. He plays the most convincing alcoholic I've ever seen on film, without question. The film built around him is certainly interesting and well-crafted, and the scenery and ambient music are both beautifully authentic. That said, I'm not terribly convinced that Under the Volcano has properly conveyed any intended deeper meanings. Is Geoffrey's behavior meant to represent that of Britain in the mid-20th century? The movie doesn't make that clear and, frankly, Geoffrey's life is interesting enough without political subtext. His final descent is a memorable one, terminating at one of the more frightening roadside cantinas one could ever imagine. Like the source novel's author, Malcolm Lowry, Geoffrey has succumbed to "death by misadventure", and it is a fascinating and terrifying process to behold.
- The film includes a clip from and several posters for Las Manos de Orlac, an early horror film.
