Actresses Posy Starling and Caro Hooper both gained a name for themselves playing fictional detective Dahlia Lively on screen - but now they are back treading the boards in London's theatre district, starring in two very different plays. Their fellow Dahlia, Rosalind King, is in the city to catch their opening weeks, but she can't help but notice some tensions between Posy and Caro. Perhaps because of Caro's new friendship with her co-star Luke Burrows, who seems to have a history with Posy. Before Rosalind can get to the bottom of what's going on, Luke is found dead. Worse, his body is found in Posy's dressing room - with Posy standing over him, covered in his blood. The West End is in uproar, but the cast of the two plays have closed ranks. Posy needs her fellow Dahlias to prove her innocence - but first she has to convince them that she didn't do it.