Adventure Time Season 8 Episode 25 - Islands Part 6: Min & Marty Episode Title:Islands Part 6: Min & Marty.Episode Description:Kara decides to take Finn to Founders Island so that he can be reunited with his mother, Minerva Campbell (voiced by Sharon Horgan). Flashbacks detail how Minerva, a nurse, met Finn's father Martin Mertins (voiced by Stephen Root) when he was hospitalized after it was mistakenly believed he was attempting to leave the island with a group of escapees. Martin and Minerva fall in love and have Finn. When one of the attempted escapees, an elderly widow (voiced by Laraine Newman), seeks revenge on Martin, he flees on a boat with Finn. When the colossus attacks their craft, the pair are separated, leaving Finn to drift away. The widow is arrested and Minerva is heartbroken over Martin and Finn's disappearance.