Starring Anne Reid and Daniel Craig. Rated 18A.

A novelist talking on CBC Radio--and it's testimony to the point being made that I can't recall her name--once explained that she made her not-quite-elderly female protagonist a hired assassin "because no one notices a middle-aged woman".

The aging lady at the centre of The Mother, a fine and subtly wrought new film from writer Hanif Kureishi (My Beautiful Laundrette) and director Roger Michell (Notting Hill), isn't a killer, or even a bad person. She upsets a lot of people, though, while making an 11th-hour attempt to break out of her role and find out who she might have been.

The superb Anne Reid, better known for British stage and TV work (she was Valerie Tatlock in the first decade of Coronation Street), plays May, a woman from Northern England whose trip to visit her grown children in London is cut disastrously short when her husband (fellow TV veteran Peter Vaughan) suddenly dies.

May goes home but can't stand the emptiness of the place. So she returns to London and camps out with married son Bobby (Steven Mackintosh, of Lock, Stock and Two Smoking Barrels), whose wife clearly doesn't appreciate the lifestyle inconvenience. Then it's on to daughter Paula (Cathryn Bradshaw), a perpetual mess lately struggling through a bad relationship with a married man.

The fellow in question, Darren (Daniel Craig) happens to be the workman fixing up Bobby's house. May gets to see him fairly often, then, and replacing her feelings of resentment at his treatment of Paula are new, half-forgotten sensations. She's pushing 70, and is it possible that a roguish man half her age, already involved with two women, might be as interested in her as he actually seems?

In the hands of the actors and the filmmakers here, not only does it seem plausible, it has a certain inevitability to it. The ensuing scenes between Reid and Craig (buffed up and proled down from playing Ted Hughes in Sylvia) are frank, and frankly romantic, despite May's description of herself as "a shapeless old lump". You know from the start that when it comes this will shock her children, who were never much impressed by her mothering skills to begin with. But what really assaults their sensibilities, and ours, if more quietly, is her refusal to go back to her former life as an anonymous woman.

I'm not quite sure what Kureishi and Michell had in mind for Darren at the end of the story; they are rather less kind to him and less clear about his character than they are with their reborn heroine. On the other hand, the movie world is packed with Darrens--but until now May has only come once a year.