The third part in what absolutely no one is calling the Night at the Museum “trilogy” turns out to be a good-natured and entertainingly surreal panto fantasy, set partly in London’s British Museum, with nice cameos from Dan Stevens as Sir Lancelot and Rebel Wilson as Tilly, the stroppy, sulky museum guard.

An opening flashback makes it clear that an explorer’s century-old defilement of an Egyptian tomb has triggered a delayed curse: an ancient tablet – resembling a keypad – is failing in its magical power to bring the museum exhibits to life. No one is enough of a spoilsport to point out that the “Epyptian curse” trope was an imperial fiction invented to stigmatise the Egyptians as irrational and malign. To rectify things, Ben Stiller’s long-suffering guard, promoted to the director of what he’s passing off as “special effects”, must take his entire gang to London to talk to the ancient Egyptians there.

Perhaps inevitably, this means a high-camp cameo as a pharoah for Ben Kingsley, and there are loads more wacky walk-ons. It’s all likable fun, and includes a bizarre sequence set inside an MC Escher drawing. There is some sharp, unintended pathos from the late Robin Williams, making his swansong as Teddy Roosevelt.