Will Dean

On a boat heading out into the North Sea, Ellen Brooke steels herself to spend almost a month locked inside a hyperbaric chamber with five other divers. They are all being paid handsomely for this work - to be lowered each day inside a diving bell to the sea bed, taking it in turns to dive down and repair oil pipes that lie in the dark waters. It is a close knit team and it has to be: any error or loss of trust could be catastrophic.

All is going to plan until one of the divers is found unresponsive in his bunk. He hadn't left the chamber. It will take four more days of decompression, locked away together, before the hatch can be opened. Four more days of bare steel, intrusive thoughts, and the constant struggle not to give way to panic. Mind games, exhaustion, suspicion, and, most of all, pressure. And if someone does unlock the door, everyone dies...

Molly lives a quiet, contained life in London. Naturally risk averse, she gains comfort from security and structure. Every day the same.

Her identical twin Katie is her exact opposite: gregarious and spontaneous. They used to be inseparable, until Katie moved to New York a year ago. Molly still speaks to her daily without fail.

But when Molly learns that Katie has died suddenly in New York, she is thrown into unfamiliar territory. Katie is part of her DNA. As terrifying as it is, she must go there and find out what happened. As she tracks her twin's last movements, cracks begin to emerge. Nothing is what it seems. And a web of deceit is closing around her.

Caz Ripley, a cafe owner from a small, ordinary town, boards the RMS Atlantica with her boyfriend Pete and a thousand fellow passengers destined for New York. The next morning, she wakes to discover that everyone else on board has disappeared. And that's just the beginning. Caz must prepare for a crossing that will be anything but plain sailing...