Detective Superintendent Jack Hawksworth is seconded by counter-terrorism to investigate a spate of domestic events. First it was needles in strawberries, then tampering of lipstick samplers and baby formula. But when toxic mushrooms enter the market system and a death occurs, a wave of terror is set to sweep the country.

There are no leads, no DNA, no witnesses, no CCTV footage. Jack and his team must work on instinct to figure out why someone would want to harm innocent victims. Scrutiny of the incidents' geography and cold cases reveals a single overlap that leads them to the death of a child in a London hospital, but little else is adding up.

When a bomber threatens the same hospital, it is up to the team to prevent the inevitable bloodshed. The clock is ticking, and no one is safe from the possibility of a tragedy on a catastrophic scale.