A few episodes ago, the NCIS team mentioned the possibility that drug cartels would use a submarine to bring drugs into the United States.

On NCIS: Los Angeles Season 5 Episode 24, NCIS teams up with the DEA to investigate cocaine worth billions of dollars being smuggled from Colombia on a submarine. Mercedes Masohn returns as DEA Agent Talia Del Campo. Her involvement in the case could prove interesting for Deeks and Kensi's partnership.

Meanwhile, Hetty goes to Washington to answer questions about the decisions she made regarding the White Ghost case in Afghanistan.

Based on the photos, two agents will find the submarine. Check out the official season finale photos for "Deep Trouble" to find out the answer.