You know the facts. The death caps, the dehydrator, the different-coloured plates. But in all the obsessing over the what and the how, the why never seemed to crystallise. Did Erin Patterson have a reason to murder four members of her husband’s family? Who is the woman at the heart of this case?

Uncertain of Patterson’s motivation and fascinated by the way stories can take on the power of truth, Kate Grenville decides to write two versions of the mushroom case. In one, Erin is cunning, vindictive, guilty. In the other, she is unlucky, flustered, innocent.

Which is more persuasive?

You be the judge.