S7·E11 C'mon I Tip Waitresses

After a taxi driver reports a passenger who seriously gave him the creeps with his misogynistic views on women, Ali decides to look into it, and the trail leads her to Ian Summerhill, a dentist who had dated the first missing woman and had been dating the woman found a couple of days after the cabbie came in. Sam tries to investigate Summerhill's dark side and heads back to her old work place, where girls entertain men for money. Ali's relationship with Paul is threatened when Ian shares some stories of Paul's mis-spent youth with her, and she wonders how accurate they are.