This is an amazing example of historiographic metatheatre--a type of postmodern, self-aware theatre that understands and presents the construction of histories as a self-aware narrative act. Here we have Robert Cecil commissioning a play from William Shagspeare (one of the perhaps dozen different spellings of his name that Shakespeare used or that were printed during his lifetime) to tell the official version of the Gunpowder Plot, but Shag finds it impossible to tell the official version, and he must navigate murky waters of truth, lies, equivocation--a complex process expounded upon by Henry Garnet, who is in the play, which involves telling the truth in response to the underlying anxiety of a question without necessarily truthfully answering the question that was overtly asked. So, the wager of this play is that there are different ways to tell the truth and different ways to lie, and that what appears on the surface to be a lie can in fact be a profound truth which would otherwise be unspeakable without the context of the surface lie.
At the same time, there is a fundamental equivocation to the play as a whole, because it is overtly about political intrigue, torture, power, and religious oppression. But in a deeper and more true way, this is a play about the loss of a daughter and the desperate need to reconnect with her--much like the bulk of Shakespeare's late plays. Judith is a kind of shadowy presence throughout much of this play, showing up to look after Shag's material needs and the give him the minor--though unappreciated--pushes in the right direction that he frequently needs. But she is peripheral throughout much of the play. It is only at the ending--which I won't spoil--that it becomes clear how much the play was actually about the fractured relationship between the father and the daughter, and the various relationships and concerns about betrayal, disunity, and the hope of uniting a fragmented nation are all equivocations for the underlying anxiety about Shaq's relationship with Judith.