Kirk arrived after a transporter malfunction brought him to this universe and sent this universe's Kirk to the mirror Kirk's native realm. Before he departed to his home universe, he convinced Spock to begin a reform. He told Spock that it only takes one person to start a revolution. Spock volunteered to operate the transporter controls so that Kirk and his three accomplices could all return to their native universe. Kirk never returned, and it was almost a century before the next contact with the mirror universe.