Justin is a major character in The Secret of NIMH and The Secret of NIMH 2: Timmy to the Rescue. 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, 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, though the whole thing was off-screen. 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.
In Timothy to the Rescue he is seen as Timothy's mentor, and leader of the Rats after Nicodemus's death in the first film, he is actually a father figure but hopes that Timothy thinks things through. Like with the Dog Killer he wanted Timothy to be the guard to keep an eye out if Killer was awake, but Timothy left his post, he was shocked to learn Jenny has the same intelligence that they have, and to realize the "Lost Six" of the formally Eleven Mice were still alive, and prisoner of NIMH. though at first, he refused to send a party to rescue them, but then realizes that they were worth the risk, when they were caught they encountered an altered experiment went terribly wrong (Martin), and was horrified that he is the culprit behind N.I.M.H. after years had passed after Timothy came to Thorn Valley.
He even had the help from Cecil to escape from N.I.M.H., he was later present of the unfolding of Tim's statue with Jonathans, seeing that Timothy had finally ended up not only his expectations of being a hero but succeeded in following his father's footsteps.
- Although Justin did leave with the rats to Thorn Valley, it wasn't seen on-screen, his final scene was when he saw Mrs. Brisby unconscious on the ground after using the stone.
- William H. Macy (from Jurassic Park 3) took over being Justin in "Timothy to the Rescue" since Peter Strauss didn't return.