T en years on from its premiere , Harry Potter and the Cursed Child has been transformed from an epic two-part play into a richly absorbing one-part production. A similar version is already running to great acclaim on Broadway but it still feels risky to tinker with a show that has come to feel like a fixed jewel in the West End. Happily, that risk has paid off and Cursed Child hasn’t lost any of its sparkle.

Admittedly, there are some drawbacks to reducing Jack Thorne’s ambitious five-hour script into a very tightly packed three hours. The plot can, at times, overwhelm. The story, which picks up nearly 20 years on from JK Rowling’s final book, focuses on Harry’s youngest son, Albus – freshly arrived at Hogwarts and determined to make a name for himself distinct from his famous dad. When Albus and his best friend Scorpius Malfoy stumble across a time-turner, the two unleash some seriously dark forces.…