Without a Trace (2002) : 5x2

Cindy Peterson, a mother who had become a stripper to support her family, goes missing after work one night, and Jack sends Elena in undercover at the strip club to learn what she can. Danny moves in to keep an eye on her after someone catches on to her spying, while Vivian discovers that Jim Peterson hasn't been completely honest with them. Jack faces censure from Olczyk over his relationship with Ann, and is angry with Ann after she admits to him that she thinks he let their relationship cloud his judgment in the Davis investigation.