Mary returns to WITSEC from maternity leave to find a new set of office dynamics. Plus, she must protect a witness who could take down one of the most powerful secret societies in the country.

While Mary works a case with a hoarder as a witness, she searches for child care.

When a witness hides out on an Indian reservation, Mary and Marshall ask a Native American detective for help tracking him down.

Mary looks after a bigamist, who's hiding from his former employer and his two wives.

Mary must prevent a drag queen from reverting back to his old ways, meanwhile Marshall is brought into an undercover sting operation.

When Mary's fugitive father turns up, his return puts Brandi and Jinx in danger. Revelations abound as Mary struggles to determine whom she can trust.

The FBI keeps an eye on Mary after her father goes on the lam seeking vengeance. Mary tries to lose the agents tailing her in order to track her father down herself.

In the series finale, Mary finds herself caught between her "model" witness and an unexpected family reunion, while radical changes take place around the WITSEC office.