And when do they? And what happens when they do? Nick Payne’s poignant tease of a play (the third successful transfer in a row from the Royal Court, but this time from the intimate space upstairs) poses a host of questions and provides several answers – and much humour as well as heartache – in a brief 70 minutes.

Touching on string theory, quantum mechanics, parallel universes and matters of life and death, this is, in essence, a romantic love story in which the protagonists bump and collide like random molecules, or the helium-filled balloons which hover overhead in Tom Scutt’s celestial design.

As brief scenes are played and replayed with subtle differences and various outcomes, Michael Longhurst’s expertly orchestrated production demands pitch perfect performances.

And he gets them – from Sally Hawkins (needy, nervy and articulate) and Rafe Spall (gentle, blokeish, down to earth – pictured) as they negotiate the multiverse of this unmissable two-hander.

Duke of York’s, St Martin’s Lane, WC2N 4BG
Tube | Charing Cross / Leicester Square
Until 5th January
£25.00- £37.50 (plus a few £10 day seats)