Twenty-four years ago, a girl died on the night stairs at St Cordula's Catholic boarding school.

Only three people know what really happened that night. And keeping the secret could prove deadly.

'I raced through it' CLARE MACKINTOSH
'Utterly compulsive' RUTH WARE
'Had me hooked from page one' JENNIE GODFREY
'Relentlessly gripping' LUCY CLARKE

St Cordula's has survived for centuries on tradition, discipline and silence. Now Deputy Head Fiona Fox is preparing to make a controversial change that could save the school from ruin.

But some traditions are dangerous to break.

Legend says St Cordula's will remain safe as long as the words 'GOD FORGIVE ME', scrawled on a chapel wall by a fifteenth-century nun before her death, are preserved.

The last time they faded, in 2002, a mysterious outbreak of vertigo swept through the school.

One girl died.

Fiona knows her death wasn't an accident.

Now the vertigo is back.

Could unmasking the truth about what happened that night be more dangerous than if it had stayed buried?

**PERFECT FOR FANS OF THE TRAITORS, CLARE MACKINTOSH AND CLARE MCGOWAN**