David was joined in the third series by Olivia Colman, Arthur Darvill, Andrew Buchan and Jodie Whittaker from the first series, plus Lenny Henry, Roy Hudd, Julie Hesmondhalgh, Georgina Campbell, Sarah Parish, Charlie Higson and Mark Bazeley were new cast members with significant roles.

Chris Chibnall again wrote the series which consisted of a brand new case for Miller and Hardy with the detectives teaming up to investigate a serious sexual assault and its consequences as the drama's Dorset community came under scrutiny. The third series was set three years since the second series.

Shooting started on 1st February 2016 and filmed mainly on location in Yorkshire with a couple of days in London.

In the 1960’s and 70’s R.D. Laing’s books regularly topped the student best-seller lists in the US. He shared the same stage as bands like the Grateful Dead and was never far away from controversy. The psychiatric establishment regularly tried to close his community at Kingsley Hall, seeing his occasional therapeutic use of LSD and his belief in metanoia (self-healing) as irresponsible and unscientific.