CURRENTLY online before its live theatre tour, Ben Brown’s new play demonstrates that drama without action can hold an audience’s attention if blessed with superb acting and a subject of intense interest.

As a play relating to what happened at the meeting of two people who played a significant part in modern history, A Splinter of Ice is reminiscent of Michael Frayn’s Copenhagen. But here the subject is not the reason why Nazi Germany did not achieve the catastrophic breakthrough to splitting the atom before the Allies but why a man who had all the gifts his country could offer would devote his life to betraying it.

In Copenhagen, the enigmatic 1941 meeting of physicists Niels Bohr and Werner Heisenberg is presented in some afterlife world. But the 1987 Moscow meeting of old MI6 comrades, the novelist  Graham Greene and Kim Philby — the “third man” in the so-called Cambridge spy ring who defected to the Soviet Union in 1963 — is anything but fanciful.