It’s an agreeable enough piece of hokum for most of its two hours, but Michael Punter’s Stagefright has the potential to have been something more.

We are in the manager’s cluttered eyrie in London’s Lyceum Theatre. The year is 1894 and the actor-manager in question is Henry Irving. The glittering audience for a revival of W G Wills’s version of Faust – Irving naturally starring as Mephistopheles – has departed, as have the other actors and the stage crew.

So the theatre is empty – except for the actor and his business manager, the former civil servant and part-time journalist Bram Stoker (not yet famous as the author of Dracula). Or is it? The building was already 60 years old at the time when Stagefright is set, with its tragedies and failures as well as successes. As a storm rages outside, odd things start to happen.

Which is all well and good. Theatre can do mysterious very competently; after all, its main business is the creation of illusion. The trouble with the two main characters is that Punter only skims the surface of what drives them and why; they remain two-dimensional. The set and lighting by Kerry Bradley and Joshua Carr respectively are excellent and both Barry Ward as Stoker and Jonathan Keeble as Irving give committed performances, Ward especially.

Director Colin Blumenau has used illusionist Ben Hart to create the special effects which multiply as the evening progresses. They don’t really work. Imagination, even the collective one of a theatre audience, conjures far more frightening images than any amount of palpable stage trickery. What tension has been built up then dissipates just before the last scene through a longish pause during which stage management bridges a three-year gap in the action.

The comedy thriller is a difficult genre in which to succeed. The comedy chiller is even trickier to pull off. This one, unfortunately, doesn’t do it.