Funny story about that. Had a group sail through and on the 3 valves times event we were on the last guy with no shields when time ran out. Restart that section and kill that guy with 2 seconds left only to realize we had to turn a final 4th valve to stop the timer. Luckily that's a checkpoint so when we respawned we had 2 full minutes to turn that ONE valve with no enemies guarding it. We shit some bricks thinking we had failed even with the last enemy dead but somehow made it. Another semi related story, did the mission on hard with a friend to help him out as he was leveling, we killed the final boss after stonewalling for a bit on the waves before it *shotgun rushers were still new and OP feeling at that point* and when we finally killed him and grabbed our loot we ran up to the control room to flip the switch and get mission complete... Only for the servers to go down for a maintenance that was pushed forward and thus lacked the server shutdown timer... Power Plant is a mission from hell.