Joe Hammond is a promising playwright, Tamara Harvey an accomplished director and the subject of child abuse in a care institution a topic so hot it seems over-cooked.

And that's the trouble with this 80-minute three-hander in the punishingly uncomfortable 503: a feeling of stale buns, almost, as 12 year-old Shaun (played by Charlie Jones, a member of the National Youth Theatre and a veteran of EastEnders as Ben Mitchell) is torn between the demands of his bearded middle-class minder, Mike, and dreams of escape.

The clumsily alliterative title conjures a world beyond the Victorian attic where Shaun is about to be interviewed by prospective foster parents, having been rejected by his mother; a world of freedom, forests and boat trips and of friendly people of an alien culture and different skin colour.

Shaun's fantasies have been stoked by a book, and there's a dispute between him and Mike as to what exactly he can see through the window in the dark. Things come to a head in a surprise show-down, but there's little preparation for either Shaun's "escape" or Mike's self-revelation.

David Birrell plays Mike with an appropriate stolidity, and Mark Springer is true to his surname as an exotic surrogate dad. I like the fact that there is no special pleading on either side, and that Shaun is obviously a boy who deserves love of some kind, even if it's the wrong kind.

Harvey draws back, too, from being too explicit in her staging, and there's nothing grim or gruesome in any of the physical or imaginative encounters. But nor is there all that much depth in them, and the lack of moral judgement in the play ends up weakening the overall impact.

Mind you, it makes a nice change from the righteous hysteria lapping round the Jimmy Savile affair, while disturbingly suggesting - if that's what we still need - that this sort of thing is going on far too frequently for comfort, not least that of the children themselves.