The American Plan, at St James Theatre The English actor - best known for playing Dr Daniel Springer in the television series Monroe - makes such a good job of playing the likeable, clean-cut Yank the audience sees at the outset that he reminded me of a youthful Ronald Reagan. It makes his gradual disintegration all the more harrowing to witness: he has big, expressive eyes that are full of unspoken terrors. He makes the transition from goody to baddy with deceptive ease. Greenberg might perhaps have added a twist too many to his Hitchcockian tale, in which nobody is quite what they appear to be - but it is so well acted, and ably directed by David Grindley, that it seems churlish to dwell too much upon it. Exceptionally strong ensemble casts can, in any case, triumph over flawed material, and this is why I think the production managed to keep me hooked until the very end. Quick is a delight as the imperious mother of Allen-Gale's supposed romantic interest, and the Brideshead Revisited star has to switch from comedy to tragedy as the darkness draws in over the stage and her own family's harrowing past comes back to haunt her. There is a particularly strong scene in which, chatting to Mark Edel-Hunt as the best friend of her daughter's suitor, she informs him of the conclusions that she has reached in a slyly abstract way. Taaffe, for her part, evinces a haunting vulnerability as her daughter, and there is a strong turn, too, from Doña Croll as a wily old maid who takes the view that, with such a motley crew, the less she sees and hears the better it is for all concerned. What the piece ultimately has to say for itself, I'm not so sure, but it is interesting theatre for all that, and it has in Allen-Gale an actor clearly destined for great things. To Aug 10; stjamestheatre.co.uk