Family Rick realises Jerry's disappearance with a sword in the garage. Same is happened to Jerry Prime, and they are indeed transferred to the anti-verse of Rick's dimension. They encounter Mr. Nimbus, who explains the sword seals the dark energy and fighting spirit of the planet inhabitants at the beginning of the series. Someday in the past, the sword was put to a Japan Yakuza group in the anti-verse by Rick, which then split into two factions. Jerry showed up one day and retrieved the sword from the renegades, ending the faction war. He could do this because he once let Rick train up his hero persona to overcome his inability...