A 40 year-old man has an affair with a 12 year-old girl and spends three years in prison. Years later he has changed his name and moved to another part of the country.
Suddenly the girl, now 27, turns up at his workplace at the end of the day. David Harrower's harrowing play presents, in real time, the confrontation which follows for the next hour-and-a-half in a bleak, litter-strewn staff canteen.
First staged at the Edinburgh Festival in 2005, Blackbird won the Laurence Olivier Award for best new play in the West End the following year and has been produced in New York and Sydney, where it was directed by Cate Blanchett.
It's not difficult to understand its success, because plays with this degree of intensity and rawness are rare. With Educating Rita and Oleanna it completes a contrasting trilogy of hit plays about a young woman and an older man, though unlike the others it's not quite a two-hander - we glimpse Ray's work colleagues in the corridor and there is a short appearance by his stepdaughter near the end.
It deals with one of contemporary society's greatest taboos and you could sense an extra tension in the pin-drop silence with which the audience watched it. But it's not all about recrimination, as the gradually emerging confusion of the emotionally-damaged young woman, Una, eventually makes clear.
In fact, as the author has indicated, Blackbird isn't even simply a play about child abuse, but can stand as a metaphor for any life scarred by a traumatic event from which it becomes almost impossible to move on.
The play demands big performances and gets them from Robert Daws and Dawn Steele, who has an exceptionally protracted monologue recalling how Una was abandoned by Ray in a B&B in the course of their elopement. Director David Grindley is reunited with the same design team that worked on his acclaimed revival of Journey's End.
* Running time: One hour, 30 minutes (no interval). Until Saturday.