On Quantico Season 3 Episode 3, Owen is approached and offered a case. The team has to protect a witness in a high profile cartel case. Their witnesses keep getting killed off before they can testify, despite being protected by US Marshals.
Owen happens to know this witness: Charlie Hill. Charlie was undercover in the Culebra cartel, and he knows them better than anyone. Owen takes Mike, Alex, and Shelby along with him to convince Charlie to testify and protect him. Meanwhile, the rest of the unit works on trying to find the mole by going after the cartel member who has been receiving the tips.
This calls for some undercover work! Deep and Celine set Ryan, Owen, Deep, and Harry up on an online dating site in order to try to catch the cartel member's attention. It works, but Ryan manages to blow his cover when he refuses to make out with the cartel member.
Ryan gets stabbed, and a sniper kills the cartel member before Owen and Harry can get any information out of him.
There are numerous attempts on Charlie's life, but Charlie is unfazed. It turns out, Charlie had a secret plan all. He wanted to go to court, but not to testify, to kill Culebra. He's successful.