Originally broadcast on BBC2 in April, Theroux reports from Coalinga State Hospital in California, home to more than 500 sex offenders, many of whom have already served lengthy prison sentences and are deemed unsafe for release. During his visit, Louis finds out about a therapy programme run by psychologists who hope to rehabilitate willing participants - but many inmates refuse to take part, with only 13 having completed the course since it began. Louis has gained access to Coalinga Mental Hospital in California, which houses more than 500 of the most disturbed criminals in America - convicted paedophiles. Spending time with those undergoing treatment, Louis wrestles with whether he can ever allow himself to believe men whose whole history is defined by deception and deceit.