Claire, Elise, Norah, and Piper dream of making it to the top twenty with the Stewards of Light, their Hero Guild. But the college students are not standard heroes. Their weird RPG powers require them to get experience to gain power. Balancing school, work, and family matters leaves the girls without much time to fight crime and grind out the levels they need.
When the whole city goes zombified hive-mind the gamer girls are left standing in an apocalyptic nightmare with no hero left to save them. The underclassmen are outclassed, but they're also the only ones who can stop the spread of chaos.