One moment, Emma Scott is in her college room in 2015, and the next she's in 1921 falling in love with an ex-soldier with a charming smile and a secret...
Emma's an old hand at time travel: the first time she was pulled backwards she was ten years old. She can sense the memories that stone, fabric and wood have soaked up: usually she just sees them, but sometimes she ends up living them. She knows the drill: (1) avoid getting pulled backwards in the first place; (2) avoid the object that's pulled you backwards; (3) prevent the memory that imprints on the object, or, if all that fails, (4) wait it out until you're back in the right time.
The problem is that the object was an old ring that her Granny Alice bequeathed to her, and Emma last saw it on the finger of her great grandmother, fleeing into a crowded London street. Now Emma is trying to find the ring and go back to her own time, but her great grandmother has vanished, and meanwhile there's Charlie Lawrence who's making Emma wonder if she even wants to go back at all...