Who Killed Santa Claus?, TinFish Theatre. This is a whodunit whose prattle about astrology, Hair, and the pill quickly reveals its age. But playwright Terence Feely’s anti-Agatha (as in Christie) innovations give this 1970 thriller a certain historical interest. In the right hands, Who Killed Santa Claus? might be a period curiosity, as swinging London personalities swap stylishly brittle speculations on the death threats against a wholesome TV hostess and subsequent murder committed at the staff Christmas party.

Unfortunately, under Dejan Avramovich’s characteristically inattentive direction, the youthful TinFish actors ignore the witticisms and flourishes that might have distracted us from the play’s structural flaws. And the production’s classroom ambience is heightened by various oddities and anachronisms–if this is 1970, why is a Chelsea apartment decorated in American southwest, complete with Moorish arches? And why is the TV star’s preferred firearm that of a cavalry officer in the Boer War?

Who killed Who Killed Santa Claus? Was it the author? The director? The cast? The decor? This is the mystery we ponder long after the play is over.