It’s Halloween night, and the Daniels have been invited to a costume ball at one of central London’s poshest hotels. Jane dresses up as the Shaggy to Kennedy’s Scooby Doo, and the couple heads off into the night to the fancy dress event that awaits.

The party is in full swing when Scooby Doo is fatally shot by a sniper bullet. Lucky for the Daniels, the victim was another Scooby Doo. But the lingering fear that the bullet might have been meant for Kennedy haunts Jane, and her angst is intensified when Kennedy escapes a killer with a knife in the London Underground two days later.

When Kennedy realizes that she knows the attacker, she is bewildered. Devon Maldon, a fellow war veteran who suffers from intense PTSD, met Kennedy years ago in an online chat group. But why would he want to do away with his pen pal?