He’s drowning, not waving!

The hunt is on for a four-year-old boy after he disappears from his garden. Did he wander off on his own? Is he the victim of a custody dispute between his separated parents? Or did a stranger take him? The Sun Hill officers are quickly on the case…

Thanks to a tip-off from a local resident and CCTV, the cops quickly establish that a little boy seen getting into a car is the missing Billy Sullivan. The car had false number plates but DS Stevie Moss and DC Jacob Banks know just where to go for information. Sure enough, a local scrap dealer admits selling the plates to Peter Grigson (Joel Beckett – Jake Moon in EastEnders). And Peter’s ex-wife reveals they’re no longer married because he was more than friendly towards a neighbour’s son. It gets worse… Billy’s dad, Ray, has been caught on CCTV talking to Peter about his little boy. But Sgt Callum Stone, at Sun Hill to discuss his suspension, convinces Inspector Smith that Ray is innocent.

That’s not the case with Peter, though. He admits he took Billy but lies about where the boy is. It takes 21st-century science to lead the officers to a storm drain next to the River Thames. Little Billy is in it – and the water is rising fast…