A year or so ago, Daniel Kehlmann’s The Mentor was so successful in this studio space in Bath that it transferred to the West End; part of that, of course, was due to the cachet of having F. Murray Abraham in the title role. Now the Ustinov’s artistic director Lawrence Boswell presents another Kehlmann play in a translation from the German by Christopher Hampton.

In some respects the subject matter of the two plays could hardly be more different: The Mentor depicted a spiky relationship between two authors, whereas Christmas Eve follows, almost in real time (75 minutes onstage represent 90 in the locked-room set), the interrogation of a woman detained as a terrorist suspect. However, since the woman is a philosophy don, the set-up allows for a relatively swift progression from the opening minutes of non-specific but immediate Pinteresque menace to more abstract discussions, not unlike those concerning literature in the earlier play, only more so. Much more so.

Kehlmann is principally a novelist, and it’s hard not to suspect that his primary interest is in the ideas with which interrogator Thomas and professor Judith begin fencing, with tics of character and situation – even the urgency of a possibly fatal deadline – being deployed consciously to leaven the mix. (The action is set on Christmas Eve largely so that most of the machinery of state repression is on holiday, justifying the two-hander format.) Nor is the conceptual side of things all that complex or original: the paranoia of the contemporary state is chilling but hardly novel, and I’ve lost count of the number of plays I’ve seen which hinge on that game-theory classic, the Prisoner’s Dilemma. My companion and I disagreed over whether the “is she or isn’t she?” switchback ends ambiguously, but we agreed that if uncertainty is intended, it isn’t very successful.

Niamh Cusack as Judith holds the intellectual whip-hand; dramatically, the honours are shared more evenly with Patrick Baladi’s insinuating, evasive Thomas. Both give assured performances, and director Boswell keeps the countdown ticking smoothly. But as regards the issues of civil liberties and social theory, we’re neither told anything new nor reminded particularly of the urgency of what we already know.

Written for the Financial Times.