Power substation (San Hieronymo Peninsula)

Missions
go up the ramp. by the building entrance there is a female officer that you may want to knock out (unless you can sneak past) nearby there is a ramp down again. you will want to use the ladder so when the patrolling guard comes by you will want to knock him out. climb the ladder and do a running roll off the ledge. This will land you on the rooftop. At night there is a female officer patrolling. Find the ladder to climb down. use the door to get inside. nearby is a room that has the MAC-10 a silenced sub machine gun. use the map to find the room you need to be in. at this point it's revealed you need a time bomb. Once you return to briefing, equip the time bomb and repeat the mission.

Boss: Null
After setting the timer you face Null for the second time.

hide behind a container, He will use three bursts of his gun before needing to reload. Shoot him while he reloads. don't let him use his machete as this will cause massive damage.