Leo and Viv's Friday night starts out like any other. A bottle of wine, a takeaway from their favourite Chinese restaurant, a movie, then an early night. But when Leo wakes up, he finds he's not in London anymore; he's naked and alone in an unfamiliar bed, in an anonymous hotel, on the other side of the world.

Viv wakes up to a ringing phone. It's Leo - he claims that he's in Australia, despite the impossibility of it. An emergency passport is arranged. A return flight to London is booked, but before Leo can make it onto the plane, there's a flicker in the corner of his vision, and he wakes up in another bed, in another hotel room, in another country.

Disoriented, Leo soon discovers he's not alone. Someone with access to a groundbreaking technology and an axe to grind is beaming a group of individuals around the globe - and hunting them down, one by one, committing perfect, untraceable murders.

As Leo fights for his life, back in London, Viv is struggling to understand what's happening. But as her investigation deepens she starts to unearth secrets from Leo's past. Dark secrets. Secrets that might be enough to make someone want to kill him. And the more she learns about Leo, the less she seems to know - and the less certain she is that her husband is a man worth saving.