Sean (Simon Pegg) has a bad career and a bad love life. He met a group of equally idle friends and hung out with them all day, including Pete and Ed, who only plays games and is annoying. Sean tried to cheer up his girlfriend, but was laughed at by his colleagues, and his girlfriend didn't understand. Sean had to continue to get drunk and have fun with his friends. But the whole city has changed dramatically that day. Zombies have invaded, and anyone bitten by them will become a zombie. Sean was drinking with Ed in the bar, but found himself surrounded by zombies. Now Sean must show his heroism to defend his family and friends.