Hilary Bryant works for Harlequin, a company based in London specialising in the history of theatre, giving advice to TV and radio, and managing old theatres, including one old mysterious theatre called the Tarleton, which has been boarded up for years, since some mysterious event back in the 1920s or thereabouts. No one seems to know what happened, why the theatre had to be shut for at least 50 years, or even who owns it. Robert, a surveyor, is asked to survey the theatre and finds a wall, which seals off half of the room underneath the stage. The stage trap, that would enable Robert to gain access to the sealed off part of the room is nailed tightly shut, also making the room underneath inaccessible, but why? He and Hilary team up to try to find out more about the theatre's past, with Hilary undertaking the research into the history of the building, and Robert deciding to sneak back to find a way into the sealed off room, to discover what's been hidden there.

Then a letter arrives from the owner, an elderly woman, finally asking if Harlequin would be prepared to open the theatre once again. Hilary and her boss, Shona, drive out to her country house to see her. But Shona has her own secrets, which we gradually find out about through the book through flashbacks. She was brought up in the country, by an alcoholic mother and very strict grandfather, and has a mysteriously absent father, and some deeply buried memories that she is finding hard to bring to the surface.

Alongside, there is also the story of Toby, an actor in the Tarleton in about 1910, and his association with an underground organisation called Tranz, who persuade him to go out to Sarajevo to join a protest rally against Archduke Ferdinand. There is the story of Toby's parents, an actress and a Lord, who met and married for love. And, one last story of Caley, a middle aged man who was adopted, but feels a strong connection to the Tarleton.

There are a lot of threads to pull together in this book, but the author manages to do this successfully. If I were to quibble, I would say that the story of Shona was just a little too far fetched, and could have been dropped without detracting too much from the overall story. The mystery behind the closure of the theatre was interesting enough, and Hilary and Robert a very likeable heroine and hero. An enjoyable book, which keeps the reader entertained the whole way through.