Mike Leigh's new play has completely sold out, despite no-one knowing what it is about or even the name of it.
Mike Leigh was Oscar-nominated for Vera Drake
The Oscar-nominated director has spent four months with eight actors creating and improvising a production for the National Theatre in London.
Such has been the excitement of Leigh's first play in 12 years that all 16,000 seats have already gone.
The National Theatre said it was "as much in the dark" about the play as everybody else.
"Details of the plot are known only to those directly involved in the rehearsal process," said a spokeswoman.
Leigh has a reputation for creating films and theatre through a workshop process, beginning rehearsals without an initial script.
The actors are asked to improvise their characters under his direction before a final production is arrived at.
He went through a similar process with his Oscar-nominated movie Vera Drake, starring Imelda Staunton.
Leigh's most famous play is arguably Abigail's Party, which continues to be staged around the world.
Preview performances for the new play begin on 8 September, running until 31 January.