Marvin and the team investigate the death of a morning TV host, in which former child star Lil' Betsy is the main suspect. In the process of the investigation, Marvin becomes consumed with his newfound celebrity status. With everyone rallying around Lil' Betsy, Marvin is determined to find her guilty.

During the town's talent show, a serial killer targets the winner as Marvin finds himself at the judging table to capture them in the act.

In an attempt to become immortal, Marvin drinks a special potion that causes rapid de-aging. Meanwhile, the department hires a new lieutenant.