Percy was fighting his way through a horde of zombies. He just wanted to get back to Estelle, who was in the care of Tyson currently. It was too dangerous for them to go scavenge, so they stayed back at the safe house.

Just when he thought he was safe, he heard rustling in a nearby bush. He unsheathed his sword, who he nicknamed Riptide. He got it from an abandoned armory.