Bulman and Willis join the new inter-city detective squad and are involved in tracking down a gang of sophisticated villains running an arms-for-sale racket out of London.
Bulman and Willis are assigned to a case involving the widespread fraud of major banks.
A routine escort job turns dangerous for Bulman and Willis when they're assigned to bring a villain to London for questioning, and two inter-city detectives are murdered.
Bulman and Willis find themselves going undercover to track down a gang hedging their bets by ensuring that the odds are in their favour during a racehorse meeting at Newmarket.
One of Bulman's criminal contacts is beaten up for no apparent reason. The trail leads Bulman and Willis into the world of counter-espionage, and a circus that chooses the towns in which it plays.
Bulman disguises himself as a tramp hoping to catch the smugglers' 'Tom Thumb' who works Liverpool docklands. He soon discovers that with a fortune at stake the organisation behind the ring will stop at nothing to protect their interests.
Bulman gets a tip-off from an informer about a hired killer. With Willis and Bennett, he tries to find the connection between the killer and two arms dealers.