After completing the Devastator quest, this one will automatically start. Once you get to the jungle, get in the car with Jin and start driving. When you get to the bridge, go down and kill all the enemies in the water. Escort Jin through the jungle, don't stop to kill enemies unless she stops. Complete the quest by getting to Matutero. There are now some side quests, or talk to him again to start the Chasing Shadows quest.
Tape - Is on the desk in front of Matutero.