It's perhaps predictable that the weakness of a first play written by a comedian turns out to be that it is really a protracted one-liner.
Nigel Planer has constructed what is essentially a two-handed comedy (the fact that the cast is doubled in a brief final scene seems a touch clumsy), on the true story of Michelangelo's assistants in the Sistine Chapel.
The fact that their names were Lapo and Loti immediately suggests a classic comedy duo. These characters are familiar hapless bystanders, recalling Vladimir and Estragon in Waiting for Godot or the Stoppard version of Rosencrantz and Guildenstern.
They don't think much of Michelangelo, the reluctant painter who knows nothing of the exacting craft of buon fresco. Lapo sets a blistering pace in pouring scorn in the face of his more moderate apprentice, who grumbles that their counterparts working for Raphael get lunchbreaks and free cake at six o'clock.
Though the invective is amusing it's getting more than a touch repetitive by the interval. And so there's a new device to launch the second act: Lapo and Loti, now fired by Michelangelo, are reduced to becoming travelling players, acting out the story of their former boss and his struggle with Pope Julius II.
With an ingenious piece of theatrical magic to round it off, the play sustains its modest length. What is quite interesting about it is the way it gently relocates a landmark work of human genius into a workaday world (and Matthew Wright's reconstruction of Renaissance scaffolding makes for a fascinating set).
Yet it doesn't in any way explain or diminish the genius. Returning to the Sisitine Chapel, Lapo and Loti are astonished by the way Michelangelo has burst through the time-honoured craft-restraints of fresco painting to cover vast areas of the ceiling in a single day.
Ron Cook is spot-on as the stroppy Lapo, Ralf Little a touch lightweight as his more conciliatory partner.
* Running time: Two hours. Until May 28.