In Deep is British crime drama series created by Peter Jukes, starring Nick Berry and Stephen Tompkinson as undercover detectives Liam Ketman and Garth O'Hanlon.

One slip-up can result in disaster, something that Liam Ketman (Nick Berry) and Garth O Hanlon (Stephen Tompkinson) know only too well.

Garth O'Hanlon is described as a character apparently devoid of emotional or family entanglements who deals with often extreme violence as part of his job.

[3] Tompkinson was forced to change his appearance radically for every episode to suit each individual undercover persona.

Whilst researching material for the series, writer Peter Jukes spent several weeks with real-life undercover police officers that infiltrate hard-core criminal operations, in order to find out what life is really like for them.