What Puts You on That Ledge

Plot:

Antonio heads undercover with a dangerous robbery crew after a narcotics officer goes missing. Commander Fischer updates Voight on a missing officer that Narcotics had deep undercover with a robbery crew. Antonio connected with one of the crew members years ago, so he's asked to reestablish contact to help them find the officer. Meanwhile, Roman and Burgess are dealing with a squatter situation and they enlist Chicago Fire's Mouch to help.