Infinitum: Subject Unknown review – solo time loop echoes lockdown

This iPhone-shot sci-fi drama with cameos from Ian McKellen and Conleth Hill is impressively realised, though the plot ultimately frustrates

You've got to admire wife and husband film-makers Tori and Matthew Butler-Hart. Stuck in their London flat at the start of the pandemic, the pair wrote a sci-fi script together: a Groundhog-Day-meets-The-Matrix tale of a woman trapped in a time loop. They shot it a deux on an iPhone; she stars, he directs. And there are a couple of cameos, from Ian McKellen and Game of Thrones actor Conleth Hill (who quite literally phoned in their performances from home). It's a genuinely impressive achievement, but for a film about the infinite possibilities of parallel universes, it's exasperatingly samey.

Tori Butler-Hart is Jane, a woman who wakes up every morning tied to a chair in the attic of a London semi with no memory of how she got there. Outside, the streets are eerily quiet. Scared but resourceful, Jane finds a door hidden behind a pile of junk. A camera on the wall is watching - and from time to time the soundtrack picks up the voices of her observers, distorted and crackling.