Revenue inspector Scott is on the lookout for fare evaders attempting to force their way through the ticket barriers. Alex and Baba join forces with the police in a sting operation along a busy stretch on one of the city's busiest bus routes.

Revenue inspectors Karen and Peter stop dishonest commuters exploiting a transport loophole.

A prolific barrier-blagger is handed an eye-watering bill for three years of illegal travel, while in east London, tube enforcement officers Karen and Peter stop passengers cheating with discounted tickets.

Undercover investigator Dan has a fresh case to crack at Kings Cross as someone pretends to `tap on' the ticket barriers with a declined debit card, before audaciously shuffling his way through the gates behind honest paying travellers.

Investigators go on the trail of a fare dodger they suspect has avoided paying for more than 600 journeys and officers monitor Hounslow trains, a hot spot for fare evasion.

The hunt is on in Surrey for a suspect thought to have evaded close to £20,000 of fares in one of South Western Railway's biggest ever fraud cases. Revenue Protection officers Michelle and Lucky expose short farers at Vauxhall. And at London Waterloo, Jack and Jack face up to an explosive passenger, while Harry has a run in with a barrier basher

Investigators Rich and Greg go on the look-out for a fare dodger thought to be scamming Transport for London for over a year, racking up more than £5,000 in unpaid fares. At Waterloo, South Western Railway revenue protection officer Sam faces a tense situation with a man caught without a valid ticket who is more focused on finding a toilet than co-operating