Justin

Justin is the tritagonist later true main protagonist of The Secret of NIMH. He is Captain of the Guard until Nicodemus's death and became the leader of the rats. He is voiced by Peter Strauss, who subsequently named his son after the character.

The Secret of NIMH (1982)
Justin is one of the original rats who escaped NIMH. He was the Captain of the Guard. When Mrs. Elizabeth Brisby comes to the rose bush for the Rats' aid, not only is he aroused by her but he is more than willing to help move her house to the lee of the stone. After Nicodemus tells Mrs. Brisby about NIMH and gives her the Stone, Justin gives them a boat ride and tells Mrs. Brisby about drugging the cat, which is how Mr. Ages broke his leg. On the night of the move, Justin assists Mrs. Brisby in drugging the cat, but she gets caught by Billy. He runs off to her house after he promises her he'll come back for her later. During the move, things get really bad and with Nicodemus's death, Justin is simply heartbroken. While mourning over his death, Sullivan comes to him to let him know Mrs. Brisby is in trouble. He charges between her and Jenner, protecting her from him. When Jenner catches his eye on the Stone, he pushes Justin away and slashes him across the upper left arm. As he strangles Mrs. Brisby, Justin rushes to her aid and kicks him to the side, helping Mrs. Brisby up and dragging her away from Jenner as he gets up again (off-screen). Justin battles Jenner in a swordfight and nearly defeats him. As Jenner gets up to the lee and prepares to send a blow above his head, Justin is horrified and is about to be killed until Sullivan throws a dagger, from a far distance, into Jenner's back and fatally wounds him as he falls from a fatal height to complete unconsciousness. When the Brisby home begins to sink in the mud, Justin and the rats get some rope and try to pull the cinder block out. It is no good and begins to sink into the mud, taking Mrs. Brisby with it. He runs to the rescue and pulls her out as she becomes devastatingly upset. The Stone bursts out from the mud and as Mrs. Brisby uses it, Justin, Mr. Ages and the other rats bow in front of her. After she passes out, he picks her up and carries her into the house, into bed. She offers him the Stone and he takes it as he takes on his new position as leader of the Rats of NIMH in Thorn Valley.

Trivia

 * Justin is the true protagonist in the film because he had bigger plans than Mrs. Brisby.
 * Some fans believed that Justin was the love interest to Mrs. Brisby in the first movie.