Martin Brisby is the main antagonist of The Secret of NIMH 2: Timmy to the Rescue. He is the older brother of the protagonist, Timothy Brisby. Of course, he appeared in the first film, just as an antihero. He doesn't start off as a villain in either film; he just thinks he's the one Nicodemus should have picked because he is older and stronger than Timmy, so he leaves the family to find his own destiny. He is captured and experimented on by NIMH, specifically by Dr. Valentine until he becomes evolved and insane enough to use the scientists' machines on themselves. Martin takes control over NIMH and uses his new abilities to turn the rats into his bodyguards and the scientists into dogs. He then plans to take over the world, but he is prevented from doing so by Timothy and his girlfriend Jenny who arrive to save him and the other rats. They defeat Martin and return him to Thorn Valley, where he quickly heals from the effects of the devices (that he kept using on himself even after the scientists were gone) and regains his sanity. He is voiced by Wil Wheaton in the first film, while in the sequel, he is voiced by Phillip Van Dyke as a young mouse, Eric Idle as his evil self, and Phillip Glasser as a reformed adult.