Season 4, Episode 10 | March 20th, 2012
It's the last day on patrol for Tang (special guest star Lucy Liu), as she prepares to move to another precinct as sergeant. But first she wants to tie up some loose ends on the beat. Lydia is pressured to make a decision about the extent of her police duties during the rest of her pregnancy. Ben and Ferguson (special guest star Lou Diamond Phillips) are partnered together, but Ben is bent on tracking down the woman he's been trying to help so he can protect her daughter from the abusive pimp controlling their lives.