After learning of the resistence present in this region and how his oncoming onslaught will need a direct path to Mann.Co's core facilities which happens to pass through this natural chokepoint. Grey Mann has designated this passage as a key location in the war and has now dispatched a full-scale invasion of the region, ensure whatever Grey Mann has planned fails by destroying the oncoming robots.

This mission features both a increase in difficulty from the previous mission and additional bot variety including it's own boss robot leading the assault.