The elderly Jim is on his deathbed, attended by a doctor and an instantly dislikable son. It’s obvious that the visitors know each other; grievances are aired, coals raked over, recriminations thrown. It’s a standard, if unseemly, family row. But why is Jim clutching a bible, and why does it matter that tomorrow is the sixth of June? As it turns out, the most important visitor is yet to arrive – and when she does appear, she’s hot in more than one way.

At first glance, Sins of the Mother is a riff on Doctor Faustus, except that the Devil appears in person and in female form. Imperious, seductive, and keen for us to notice her impeccable hair, she is every inch a Satan for the modern age. But this clever script from playwright Freya McCall packs in more intrigue than at first it seems… because the deal that’s been struck is an unusual one, and there’s a certain depth of evil that even Lucifer abhors.

Molly Gilbert plays Satan with delicious glee: comically impish, gloriously mercurial, and filled with childish excitement at the thought of human sin. It’s an energetic, heightened performance, which still finds room for sensitivity – Satan was cast out of Heaven, after all, and deep down that rejection still burns. As the story develops, we not only discover some sympathy for the Devil, but begin to wonder whether the Devil might be swayed by sympathy too.

If there’s a flaw in this play, it’s that Satan is too dominant. There are other interesting characters here, with complex motivations of their own, and Rae Webb’s portrayal of the innocent child Darcey is especially affecting near the end. But they all fade a little into the shadow alongside Gilbert’s demonic live wire. It’s a shame, because McCall’s plot brings out some fascinating themes: the ends and the means, the quiet power of sacrifice, and the terrifying thought that a handful of people might not regret selling their soul.

The true nature of the secret deal is a little too clearly telegraphed – but the deeper mystery surrounding it is still intriguing, and there’s tension and uncertainty right up to the end. So, while Sins of the Mother can be wickedly entertaining, it’s a well-worked dark thriller too. Hot-foot it to the box office, though… it’s only here for a week.