Two queens. One in power. One in prison. It's all in the execution. Schiller's political tragedy takes us behind the scenes of British history's famous rivalry between Elizabeth I and Mary Queen of Scots. Written in verse and based on historical sources, Schiller's play imagines the queens' lives - one in court, the other in prison - surrounded by staff and servants. Their imagined meeting, before Mary's execution, is passionate and enthralling.  Robert Icke's lean version condenses the action, cutting the cast to twelve, whilst retaining the play's symmetrical structure and tense atmosphere.    In an exciting twist, the first production had two actors learn the roles of both queens, and their roles were decided at each performance by the toss of a coin. Adding a further duality to the play, this also allowed the first word of the evening to anticipate its ending:'Heads'.