After a nuclear attack, seven dwellers of an apartment building seek refuge in a bunker in the basement of the building where the super, Mickey, lives. He rations water and supplies among the group formed by Eva and her boyfriend Sam; young men Bobby and Josh and his brother Adrien; Marilyn and her daughter Wendi; and Delvin. When five invaders break into their shelter wearing protective clothing and breathing apparatuses, they abduct Wendi but the survivors succeed in killing two of the men....