The lurker

You lurk around the back, and slip into the water. You swim under the dock, and look into the cracks between the boards on the docks. You see a man above you, and you grab through the boards and pull the man down. You swim to a different location before they start shooting again and pull another man down, and another, and another. You pull about 20 men down and knock them down and put them on the disgusting sand. You crawl back out and go on the dock. You see a the rest of the men, and before they start shooting at you you run behind a concrete barrier. You take out your pistol and start firing at them. They shoot at you, you then shoot back and take out about 10 men. Only 20 left. You grab a grenade out of your pocket and toss it at the men. You had this gernsde for a little while. You throw it and kaboom everything and one explodes, but you see pronto managed to stay clear of the blast and he starts charging at you what do you do?