Terror stalks the streets of London.

When a bomb explodes on Oxford Street on Good Friday, the force of the blast brings down a building, trapping dozens under the rubble. The whole capital grinds to a halt.

Teamed with her new explosive detection dog, Otto, PC Lucy Halliday is against the clock to prevent a second tragedy. Meanwhile, DCI Jack Ellis is pulled on to the case too – his former experience in counter-terrorism isn’t just a bonus now; it’s a necessity.

The race is on. Can Jack and Lucy find the bombers before London is hit again?