Playwright Mike Bartlett has been inspired by Edward Snowden's massive leak of American classified documents. His engrossing play becomes more convincing the more outlandish it gets. And it gets really outlandish.

It is set in the kind of Moscow hotel room widely thought to be Snowden's home soon after he became a fugitive from the United States, and presumably the secret services of many other countries. Here the weary American - brimful of principle and naivety, and called Andrew - receives consecutive visits from a mysterious man and woman who each claim to be working for Julian Assange, the man who facilitated Snowden's leak, though he's not actually named..

As Andrew (a terrific Jack Farthing) says, nothing and no one can be trusted. Institutions will soon fall. Calamity, hitherto confined to such places as Ukraine and Sudan, is coming our way. And seen, as I did after Brexit, as opposed to the press night which was before, the play feels eerily spot on about our future.