Both detectives are published authors. Blake's poet, Stephen Protheroe, is a tormented soul mate to your poet, Gabriel Dauntsey. Both are book editors. Blake's Millicent Miles is sister to your Esme Carling. And both ladies are both slashed to death by a poet's hand.
All mysteries worth the name end by unmasking the killer.
But some shed more than one mask. In an artistic flourish of symmetrical precision, the circle of coincidence is joined by each book's last chaper. Alas, Baroness, I regret that I could not be more helpful as your plot-maker. E-mail this story to a friend.