The image of the ship of fools was a much-loved medieval device that allowed satirists and artists to attack the powers of their time - which meant, by and large, the church and its instruments. It's an approach that playwright Andrew Bovell (a name you might know from Strictly Ballroom) has harnessed for the modern age in a play of that name which opened last Friday at the new Theatre 503.

One half of Bovell's tale is of 1492 Basel, known, as one of its burgher proclaims, "throughout Christendom for civility and sophistication", when the city council decides to get rid of the mentally ill, the disabled, and the heretic by putting them on a rotting, oarless, sailless barge and pushing off to an unknown fate. The other half is in modern Britain, in which the off-stage powers-that-be decide to ship a mismatched group of unemployment benefit recipients off to a mysterious job-creation scheme that might or might not be in Scotland.

Bovell's not only visiting the Middle Ages, but harnessing much of their rambunctious, scatological energy. Central to the historic tale, and linking together the centuries is the Fool (Andrew Buchan), who morphs into the modern-day delinquent Simon. One piece of dark comedy concerns the "mooning" to which the Ship's passenger's subject a bunch of well-meaning nuns; one running joke concerns the uncertain bowels of the mayor of Basel.

The language of Ship of Fools is poetic, almost Shakespearean, although in the sense of mischief there's more of Marlowe. Effective use is made of the repeats of whole passages in the two ages, with the image of the "half-built, half-broken-down" settlements in which both groups of misfits find refuge sticking in the mind, as are such philosophical notes as "a stranger in the company of the strange will at last belong".

This constant shifting across five centuries is challenging, but Toby Frow's production and the cast by and large handle it well, even in the tight, in-the-round confines of Theatre 503. Yet this is a play that might really blossom further on a larger, more conventional, venue - declamatory monologues are a tough ask in this setting, and Buchan at times struggles with the challenge, although his confidence grows as the evening progresses.