This trophy requires you to rescue Lauren as well as yourself (while playing as Scott Shelby). Progressing through the story, you'll soon have the character come to in his car underwater. Struggle with the restraints until you get the option to play around with the dashboard. From there, turn the car on, then prime the cigarette lighter. Fumble around with it until it helps you burn through your ropes, and then try to free Lauren. Remove her restraints, and then break the glass. Shelby will carry the woman with him to the surface.