Welcome to my "Hole in One" Achievement Guide. For this you have to throw an enemy into the sink hole, which is located after the second Alien pipe thingy on the way to the third pipe, during the mission "
Dark Heart". Once there you need to grab an enemy, jump down near the hole and chuck them down it. If you mess up just get yourself killed and restart the save. I hope this helps. This is tricky and may take a couple of attempts. Cheers!
