When the secrecy of a nuclear weapon agreement is thrown into doubt, a disgraced intelligence operative is recruited to find out if the deal is still safe… Ali Sinclair, wrongly convicted and on the run from a Mexican prison, is enlisted to infiltrate her old friend's inner circle and find the evidence. The only people on her side are an ex-Cold War spook and the former Royal Marine that was sent to find her. Together they discover that the stakes are much higher than anyone knew, and the fate of the world is at risk… But when you've lived in the shadows who can you trust?