Scavenge is an incredibly fast-paced and potentially short mode. If your team is disorganized and you don't manage to get any gas back in time, well, it lasts about a minute. And since the gas cans are scattered all over the place and you need to split your team up to find them, getting yourself and the gas back to the middle in one piece is a dicey proposition. Seasoned Left 4 Dead players know that splitting your team up often means certain death. Scavenge is going to take some teamwork.