'Endangered Species'
The only time the series let me down is when Frost dated, or at least was trying to date a 31-year old fitness instructor, when he is a frumpy 66-year old soon to be retired copper. Even though he's charming and caring he is still her grandpa's age. I somehow found that rather odd. The pairing of the ex-madam was so much better than this mess, IMO.
The rest of course is pure brilliance.