All according to plan... 10

Aaarrrgh!!! I’ve sniped everyone a dozen times no chievo. I’ve done the grenade over the cliff walls with skulls a dozen times no chievo. I’ve killed all my marine before trying and done all of the above no chievo and I’ve signed in a guest controller and done all of the above STILL NO @$%!! ACHIEVEMENT. I’ve been at this for weeks straight its the only halo achievement I have left across all games. I got everyone the music starts I get nothing. With the grenade over the cliff trick its impossible to see me the music still changes after I kill everything but still nothing. I’m at the point where I’m going to delete my game data and start over but I don’t wannabe lose everything I’ve scanned into my library. Any suggestions before my last ditch effort?

This video helped me a lot, hope it helps you.

Took me a couple of tries. Shouldn’t be that hard man. You can’t miss any shots or that will alert them… Pick them off when they are isolated by themselves.

I got this on my first or second try. The key is to remember to stay far enough back so that your shots aren’t overheard. And you can’t miss any shots. Also, sometimes there is a grunt who is sleeping behind the rock ledge on the right. You have to make sure to get him as well or else you won’t get the achievement.