Two missing children. One dead curator. A devious killer who knows how to stay one step ahead.

Detective Markham gets a call from his colleague in London - and knows his plans for a peaceful Christmas beside the fire are about to go up in flames . . .

Fourteen years ago

Nine-year-old twins Annie and Dominic are playing hide and seek, through the twisty halls of the Tower of London - as someone watches from the shadows. But by the time their mum comes looking for them, it's already too late. The twins have vanished without a trace.

Now

Margaret Esdaile - the Tower's brilliant curator - thinks she's finally uncovered the truth about what happened to the twins. She calls Markham's colleague, promising him a new lead that will blow the case wide open. But she fails to show up to their meeting.

Hours later, she is found dead in her office. A pool of blood stains the papers spread across her desk. Margaret's been silenced.

She devoted her life to uncovering the darkest secrets in the Tower's long and bloody history. Which of them was worth dying for?

It's up to Markham and the gang to find out before history repeats itself . . .

This enthralling mystery is perfect for fans of Elly Griffiths, Faith Martin, Frances Lloyd, Clare Chase, P.F. Ford and LJ Ross.