Third and Final DLC Council Mission.
For me this Mission came 1 Day after Completing the 2nd DLC Mission. This Time you have to shut down Generators while Facing many Aliens (17 on Easy ) . Simply Shut Down all the Generators and Kill all remaining Aliens to End the Mission... not much more to say :)..
It is also worth Mentioning that you get a TON of Alien Resources for Completing this Mission... use them wisely :)