Walk with me: "Forget Me Not"

Alexander Holt and Lance Roehrig's low-budget Brit indie Forget Me Not follows in much the same footsteps as Before Sunrise, Once and (in particular) the glossier Last Chance Harvey, which sent Emma Thompson and Dustin Hoffman on a matchmaking walk across London. Here, it's depressed musician Tobias Menzies, walking barmaid Genevieve O'Reilly home after rescuing her from an aggressive drunk - she, in turn, rescuing him from the overdose waiting for him back at his place.

Familiarity is never far away, yet the writers change the game and raise the stakes a little by having the Grim Reaper stalk the leads. Thirtysomething Menzies - acutely aware he's now halfway through his life, with only a battered guitar case to show for it - breaks off from his pillpopping to recount the sad history of a father who was killed in the first Gulf conflict (a wrinkle destined to make every last viewer feel ten years older than they are). Meanwhile, O'Reilly's attempts to get through to a mother descending into Alzheimer's offer up a role more deserving of Gemma Jones's participation than Woody Allen could come up with in You Will Meet a Tall Dark Stranger.

Certainly, Forget Me Not skews more adult than its predecessors (Harvey excluded), and the leads do a good job of suggesting grown-ups either weighing up or burdened by their position in the grand scheme of things. Menzies gives us flashes of charm, more often obscured by a hazy somnolence that chimes with later narrative revelations; and while O'Reilly makes an unlikely barmaid - even if she is Antipodean - she's not short on the vivacity that might pull someone out of a funk.

Londoners may find the precise nature of the couple's meanderings a little vague - these two appear to stroll from Farringdon to Covent Garden without breaking a sweat - and roll their eyes when the film arrives at the South Bank, which ever since Four Weddings... in 1994 has become a rather familiar destination for lovers. (Thompson and Hoffman ended up there, too.) Yet Forget Me Not has at least one hero on board in director of photography Shane Daly, who paints an appealing, romantic picture of a capital where everybody looks glowing at six in the morning, even after a night on the tiles.

There are niggles. We're not supposed to care that Menzies is clearly miming to the song his character trills while riding the London Eye, nor that the lavish orchestration we hear on the track could only be coming from the Philharmonic in the next pod down; and it's hard to buy Jones's care home, with its resemblance to the foyer of Le Meridien. (A film like this needs a certain airiness to succeed, but here we find Holt, Roehrig and Daly giving a location too much light and space.) Yet the wrong notes and false steps in the central relationship are few and far between: the final scenes even succeed in subverting the Four Weddings saw of lovers caught in the rain, plotting a surprisingly deft, even touching course through what could so easily have become soggy terrain.

Forget Me Not opens in selected cinemas from Friday.