Finishing the assignment in 2:30 minutes earns you a 1.07 point modifier.
The objective here is simple enough – take out all twelve of the targets (or as many as you can manage) including the primary target – in under two-and-a-half-minutes! Yeah, that does sound challenging, doesn't it?
The primary strategy is to do this quickly and without alerting any of the other guards to your assassinations if you can at all help it, getting as deep into the targets as you can manage as quickly as you can manage.
The best strategy here is to take out the targets in the following order:
Basically that means you need to finish the level with at least 12:30 left on the clock – but that does not mean you actually have to take out all of the guards to complete it, you just have to be sure you take out the primary target. The rest can run and you still complete the mission, and in well under the allotted time!
If you have any trouble with this, watch the video embedded below, as it provides you with a textbook example!
Remember this is not about killing everyone, it is about killing the target and ending the mission before 2:30 has passed! Bearing that in mind you really should have no trouble with this Challenge, just be sure to make the primary target a priority!