Unusual choices of two seasonal shows put Catholicism unexpectedly centre stage in London theatre. In the final scene of one, a piece of wall falls down to reveal a hidden monstrance, while the other closes with an image of a sunlit altar set for Mass.

Beyond this coincidence of design, the plays suit double billing because they concern Catholic women killed for their convictions: Friedrich Schiller’s Mary Stuart (1800) and George Bernard Shaw’s Saint Joan (1924).

Those lucky enough to go to both shows will find themselves thematically seeing double. But the revival of Mary Stuart, by adapter-director Robert Icke, is, on its own, driven by twinned images. Juliet Stevenson and Lia Williams, dressed identically in black velvet trouser-suits and white blouses, enter from opposite sides of the stage. After the toss of a coin, the courtiers bow to the actress who will play Elizabeth, while the other becomes Mary. Tellingly, we never know which role the actor regards as a win or a loss.

The flipping of sovereigns to decide which of two performers plays a part is not a new theatrical device, but has a thrilling resonance for a play about cousins whose fates hinge on changes of side and in whose profession having their head on coins is an occupational hazard. In the key Act III scene, when the women first meet, Mary tactically appeals to a fellow member of the queens’ club, who recognises the connection but rejects it.