August, 1856. Wilkie Collins and Charles Dickens are spending the summer at Knebworth House, the magnificent Hertfordshire home of fellow writer Lord Edward Bulwer-Lytton, where they are putting on a charity performance of one of Lord Edward's most successful plays, The Lady of Lyon. But the dress rehearsal is disrupted by the discovery of a body lying in the centre of the stage, shot to death.

With everyone involved in the play coming under suspicion, the two writer-sleuths feel compelled to investigate. Their enquiries unearth a number of scandalous secrets lurking among the writers, artists and actors assembled at Knebworth. Secrets that stretch back more than twenty years. Secrets that will have devastating repercussions for the present.