Does anybody know the name and/or title of the episode where Olivia goes undercover as a prostitute? I have been up all night trying to find it?!! It's now five o'clock in the morning....I am going to bed. Please write or e-mail me a response thank you so much for your help.

It's Strain. And in the future, you may want to check this thread...

http://forums.usanetwork.com/index.php?showtopic=384675

Thanks so much for the answer, I thought it was that one but I was doubting myself. Thanks a bunch!!