The Tories are in Manchester, and thousands have turned out to protest their presence.
In the midst of the peaceful protest, a small group of hired troublemakers are planning to cause trouble. They want to start a riot, to distract from the demo's message, and usher in new laws.
Irwin has been working with an MI5 agent to track them down before they can do any damage. But now, she has been stabbed, and he is trapped in a big crowd being held on a square by Police. Just the right place to start a fight.
With the reluctant help of Kay Wood, Irwin must track down the troublemakers before it's too late, and find out who stabbed the MI5 agent.