But there the comparison ends. Sean's fateful meeting with Don Pepe erupts into the two other discrete stories in this triad of tales. It collides with the innocent lives of Rosa and her family, and the 13-year-old street kid Vincente, in a convergence of circumstances that are almost inverse to the escalating tensions of The Beach.
Did The Tesseract start with the idea of Mister Sean meeting Don Pepe, I asked Alex Garland when we met in a North London cafe, or did it begin with the unusual triptych structure of the novel? "I started with the three stories. The idea of The Tesseract's plot was much less vague than that of The Beach. I knew there were three separate stories, and although they changed a lot in the process of writing, that idea was always central to the book. I have a very clear idea of themes - generally, there'll be some sort of argument milling around my head for maybe a couple of years until it becomes more and more concrete. That's the point when I feel I have the themes for the book which I then write."
I ask if his themes are paramount. "Absolutely," he agrees. "I had a clear idea of the theme before I started, and the stories are there just to illustrate the theme."
This comes as somewhat of a surprise, since The Beach, I suggest, displays the uncluttered devotion to narrative that drives any good airport thriller. And the limpid, cool prose of his new novel does not feel over-burdened with profundities.
He relaxes visibly. "The story has to come first," he says. "I wouldn't want any other `levels', for want of a better word" - and he glances away, nervous of pretension - "to be invasive into what I would hope is the grip of the storyline."
Alex Garland chooses his words carefully. Just as the beach had served as a literary device as much as a landscape in his first novel, so The Tesseract could be set in Leeds or New York without altering the themes elicited by his characters' lives.
The basic plot must engage. Beyond that, it is for the reader to unearth any underlying axis. "I try very hard not to over-write," he explains, deferring to J G Ballard and Kazuo Ishiguro (whom, with J D Salinger, Garland cites as influences). Probably the most crucial lesson he learned about writing he attributes to Ballard and Ishiguro: "They don't signpost their themes."
This respect is reciprocal. Praise from both writers adorns the cover of The Tesseract, while Jim Crace and Ballard have likened Garland to Graham Greene. "That was one of the best things that's ever happened to me in my whole life without a doubt," he interrupts, proud of the accolade. Offguard, I demur. The comparison struck me as untrue - or, at least, not entirely accurate, I suggest, backpedalling. We agree that Ballard was probably alluding to Greene's exotic locations.
I meekly suggest Lawrence Durrell's subtle shifts in perspective as a closer parallel. Similarly, Garland's motif of the "Black Dog" serves as a mobile emblem for myth itself, and the way in which the apocryphal tale can survive in the domain of popular belief. "It's explicitly evident in the Don Pepe character," Garland agrees. "There's a myth that he had someone's hands chopped off that is relocated according to wherever he is - so some think this happened on his sugar cane plantation, but if the context in which they knew Don Pepe was his Manila docks protection racket, then they think it happened to a dock worker instead of a cane cutter. These incidents can be transplanted - and believed."
Joseph Conrad is the other obvious comparison to make. Garland claims mild shame at having read very little of Conrad, but turns my question to attack those commentators who suggested that The Beach was heavily influenced by Coppola's film Apocalypse Now. "It wasn't. It was a discussion of it, a comment upon it."
But surely, there is that point of "amok" that seems to fascinate him, when hysterical violence suspends rational action? He nods: "It's a Filipino word. Several of my friends had read The Beach and found the climax [the beach-dwellers turning on Richard and stabbing him with machetes] unnecessarily stark." He is satisfied with this: "It was important that Richard's Vietnam- influenced fantasy of glamourised violence had its comeuppance. When something violent happens, it is stark. There's a problem in general with the way in which violence gets depicted. I think it's very hard to do it in an unglamorous way."
The undertow of violence emanating from Sean's hotel room, which plaits the innocent lives of others into his own disaster, furnishes Garland with his theme for The Tesseract. "In intention, the argument behind the book is an argument in favour of atheism. All the characters are struggling with something they are trying to understand, and they attribute to it a meaning they're not quite able to grasp. What the book is arguing is that there isn't by necessity any meaning at all."
"Sometimes people just have to accept that bad things happen for no reason," Garland clarifies, trying to remember an apt line from Darryl Pinckney's novel High Cotton. "If The Tesseract could be reduced to one line, that would probably be the line. The horror that is visited on Rosa's family is not something they have brought upon themselves in any way. They didn't deserve it or ask for it. But everything that happens to people in the book can be attributed to cause and effect. There's no overarching moral architecture beyond that."
This is a minor vindication of my earlier faux pas. Graham Greene is at his sharpest when engaging with ethics or contemplating, as he recalled in his autobiography Ways of Escape, "the appalling strangeness of the mercy of God". Garland, on the other hand, polishes his limpid prose with this stark demonstration of how coincidence holds no moral dimension.
Being compared to Greene by one of his favourite writers might justifiably go to Alex Garland's young head, but he remains phlegmatic. "I had a huge amount to learn when I was writing The Beach and I still have a lot to learn." The massive success of his first novel has bought him grace to write the next two books, if nothing more.
"If you realise that writing is what you want to do, and simultaneously realise how hard it is to do financially, then to be given the opportunity to continue is a huge relief." His guardedness is typical. "People rise and sink with clockwork regularity," he adds; but he is young, and The Tesseract is unlikely to tarnish his reputation.
As Alex Garland stubs his cigarette to leave, I can't resist mentioning the set piece that I find most enchanting as a piece of literary cinematography. As Sean opens the hotel door to Don Pepe's gang, convinced they have come to kill him, a vacuum slams another door shut at the end of the corridor. Don Pepe and his cronies automatically look away, giving Sean two clear shots.
"I'm so pleased you mentioned that," he brightens with delight. "My background is in comic strips, which are incredibly influenced by film. I think in terms of panning shots and fades. That cinematic moment is absolutely related to a similar railway-carriage scene in a Hitchcock film. As Sean opens the door, everything the viewer would expect is that the guys are looking straight at him - instead, they're turning away, and Sean has this strange sort of no-man's moment in which he has time to act."
But his cinematic interest knows its place. Has he been involved in Danny Boyle's film of The Beach? "Absolutely not. That's his job, and he's better at it than I am. For as long as I'm able, I write books."
Alex Garland, a biography
Son of Garland the cartoonist, Alex Garland grew up surrounded by cartoon books. He studied history of art at Manchester University, where he spent a lot of time writing and drawing comic strips. Since then, he has travelled extensively in the East and can occasionally make himself understood in Manila's Tagalog dialect.
Published in 1996, his first novel The Beach has already sold over 275,000 copies in paperback. Film rights have been sold to Danny `Trainspotting" Boyle, and it is rumoured that Leonardo diCaprio has been offered the lead.
At 25, Garland spent almost a year grounding himself in science. This provided the geometrical motif for The Tesseract, which took two years to write. He is 28, and lives in London.