On one side the river provides a wall and moat to prevent attack from that direction, the ocean out front gives him a clear view of that side and the far end was bordered by the tracks. This was now secured by another group of drones and he zooms in on the train still parked there. He hadn’t noticed when he was there the night before but there are two train engines parked there. One with carriages and one without. The one with carriages looked empty for now but it was obviously part of Mark’s invasion plan. Then Steve starts to piece it together.
Steve: This was his way in. Damn it! They’re gonna ride the tracks straight into the heart of the city.
He zooms out and drags the view along the roads leading towards Dublin to find the army