Warren participated in the invasion on Altavilla, along with the rest of the 82nd. In Altavilla, he was stationed with a small unit, led by Captain Peterson. After some target practice with Lt. Brown, Derrick's unit moved up the hill, until they were ambushed by a Panzer. Derrick and the rest of the survivors entered the trenches, while Peterson stayed back and laid down cover.
At some point in the trenches, Derrick's friend Brown was killed by a couple Germans, leaving him and his another soldier alone. While following the path up the hill, a plane fell out of the sky, just meters away from Derrick. This blocked the path, forcing them to make their way up another hill. At the top of this hill, Derrick rendezvoused with Peterson. The two then made their way up the mountain, watching each other's backs.
They eventually reached the top of the mountain, where Derrick targeted some enemy Panzers with his binoculars.