A lone armored truck drives the night streets of Gotham. An ambulance drives up behind it and the drivers pull over. However, the ambulance drivers pull out a gun and blow out the truck's tires. They then hurl a gas bomb into the truck causing the drivers to pass out and crash. A trio of criminals crawls out of the ambulance and steal its cargo. They muse over how easy the job was but Batman comes to disillusion them of that notion. The crooks put up a fight but Batman manages to force them to crash and proceeds to apprehend them. However, one of the criminals takes hold of the stolen cargo: a surgical laser, and fires it at Batman. Batman's cowl is grazed and though the laser malfunctions, Batman is thrown off balance just long enough for the crooks to throw him from the bridge. They believe Batman is dead, but he luckily managed to land on a trolley car and escapes.
The thugs run off to Rupert Thorne who is going to see a doctor, Matthew Thorne, who specializes in helping criminals. Rupert is skeptical that his thugs managed to kill Batman but he's got other things to think about. He gives Matthew the medical laser but Matthew is upset. Rupert mentions how they're brothers and he thinks that there is no reason for the contempt. However, Matthew relates on how he failed to report a bullet (as is required by law) that he removed from Rupert on his insistence and for that he lost his license. Rupert is unsympathetic and starts yelling at Matthew but he starts having heart problems and falls to the ground.
Meanwhile, Leslie Thompkins treats a few patients and is visited by Batman. Batman falls to the ground in front of her and she diagnoses him with a concussion. She prescribes him some medicine and tells him to stay in bed the whole day but she knows that he won't and reminisces on how Thomas knew Bruce was stubborn too.
Matthew takes some x-rays of Rupert and explains that he has a heart tumor that's pressing against the aorta and restricts the flow of blood into the heart. He tells Rupert that the only way that he can save him is to take him to the hospital but Rupert refuses. Not wanting to see his brother die and eager to recover his license (which Rupert promises him if he helps) Matthew talks about Leslie Thompkins whom can help him. Rupert sends his thugs over but Matthew insists on going with them.
Rupert's thugs go to retrieve Leslie who knows about Matthew's criminal activities. She refuses to help save Rupert and Matthew allows the thugs to take her by force.
Back at Rupert's hideout, Leslie and Matthew prepare for the surgery. Leslie is skeptical that Matthew will really get his license back but Matthew is sure his brother won't turn on him. Meanwhile, Batman checks a fabric sample and learns that the thugs were working for Rupert Thorne and wonders why he would want a surgical laser. Deciding to pay Leslie a visit, he and Alfred find the entire place in shambles. Searching the room, they find a picture of Leslie and Thomas when they were still in medical school. Reading the message on the back, "Thanks for all the good times with my two Best Friends. Love, Matt." Alfred remembers that Matthew was a colleague in medical school. Bruce looks up the school's yearbook and finds Matthew Thorne's picture. Realizing the connection to Rupert, he deduces where Leslie is.
The operation a success, Matthew and Leslie leave the operating room. Unfortunately, Rupert had left his thugs with orders to kill Leslie once the operation was over. Batman arrives outside of the building but one of the orderlies catches him and attacks. Batman is still suffering from his concussion and finds it difficult to fight the orderly. Things only get worse when the orderly manages to get hold of the surgical laser and starts firing on him. Fortunately, Batman manages to beat him.
While Batman deals with the orderly, Matthew wants to leave Leslie alive and take her home but the thugs say that if he interferes with them killing Leslie the deal is off. Matthew agrees to let Leslie die but says he wants it done his way: he'll give her an injection which will be quick, painless, and can be made to look like she died of a heart attack. Leslie is unsurprised at the fact that she'll be killed and disgustedly calls Matthew no better than his brother. However, Matthew sticks Rupert's thug with the injection causing him to pass out. Matthew then tells Leslie that they have to leave. She's surprised that Matthew sided with her but he says that his license isn't worth a person's life. Leslie's relived believing that Matthew is back to his old self. Unfortunately, the thug is discovered by another thug and he calls for help. Matthew and Leslie make their way up the elevator to the roof of the building while Batman arrives and handles the thugs. Unfortunately, one of them manages to get into an elevator and onto the roof.
On the roof, Matthew manages to jump to the next rooftop but Leslie isn't sure she can and only leaps after the thug starts firing at her. She jumps but was right about not being able to make it and just barely manages to grab onto the edge. Matthew tries to hold her up but the thug gets ready to shoot. Fortunately, Batman stops him. Unfortunately, Matthew is unable to hold onto Leslie and she drops. Batman, however, is able to save her before she hits the ground.
Later, Matthew is in jail and receives a visit from Bruce who is willing to help with the legal costs and put in a good word. Matthew is skeptical about Bruce's intentions however, and when he learns that Bruce wants something he promptly refuses. Bruce tells him that he doesn't want anything illegal. When asked what, Bruce replies, "Something you know. Something only you can give me. Tell me about my father." Matthew is only too willing to comply.