When Grim misuses his powers to play bowling with asteroids, he is taken to the Underworld court and sentenced to 50 hours of community service. At a retirement home, Billy, Mandy, and Grim go to the supernatural wing, which is the Home of the Ancients, a place for retired, geriatric monsters. Grim meets his childhood idols, the Bride of Frankenstein, Dracula, and the Wolf Man. Despite Billy's comments that the old monsters are finished, Grim sets out to prove that they are still scary. Grim tries to scare a bunch of kids in the woods, but the old monsters ruin his attempt and he walks out on them.

When vampire hunter Lionel Van Helsing prepares to kill Dracula, Billy, Mandy, and Grim arrive to stop him since Dracula is just senile and harmless. Van Helsing reveals the source of his hatred: in the past, he and Dracula were "best friends forever", until Dracula used his irresistible dance moves to marry Tanya, the woman of his dreams. Tanya arrives too, revealing that she is none other than Irwin's grandmother, making Irwin one-quarter-vampire on his father's side and half-mummy on his mother's side. Van Helsing leaves, but Dracula is unsatisfied with his newfound family of nerds.