A death threat hangs over Britain's tennis ace.

It's a week before the Wimbeldon Tennis Championships and all eyes are on British hopeful, Will Anderson. But when a murder investigation leads police to a stash of mutilated photographs of Will, it becomes horribly clear that he is the murderer's next victim.

Then Police Investigation Squad trainees; Alex, Danny and Maddie go undercover with Will and things turn nasty.

Alex, Danny and Maddie - three teenagers fighting crime on the streets of London.