Untouchable

" is the second episode of the third season of Batman Beyond. It depicts the appearance of The Repeller. A strange villain appears in Gotham stealing isotopes from various locations. Batman is instantly after him but discovers that the man is surrounded by a force field that can't penetrated by anything. Meanwhile, Terry finds a new interest in Irene, a girl who has an immune deficiency and therefore has to wear a belt projecting a field very much like the Repeller's.

Plot
Out at a Gotham research facility the guards are confronted by a mysterious man that floats down in front of them. They fire upon him but he's unhurt by their gunfire and easily repels the guards away. He continues further into the facility and breezes through an electrical field. Walking on, he heads towards the isotope lab and accidentally activates a security door but it bends upon touching his force field. Batman shows up and tries to stop the man but his bolo cables are quickly snapped and a batarang simply deflects off the field. Batman tries to stop the man himself but is stopped in mid-air and hurled into the wall. The man then reaches into a vat filled with a liquid that is thousands of in. Unharmed, he flies out of the room. Batman gives chase but still can't harm his enemy. During his escape the Repeller knocks over a billboard and Batman is forced to back off in order to save the people below.

Back in the Batcave, Bruce explains that the Repeller stole the only sample of an unstable isotope: Beta Sterillium. Terry explains that he's never seen anything like the Repeller's powers but Bruce claims that he has.

Together, Bruce and Terry go the Wayne-Powers Medical Research Facility, which has a special clinic for people with deficient immune systems. Because these people are so vulnerable to infections, they cannot be allowed out into the world without protection. Bruce and Terry are guided by Dr. Suzuki, who explains about the solutions they've been working on. The older "bubble suits" were too cumbersome but they have come up with a new solution: the ISO Field Generator Rings. These rings are said to "create a dia-gravitational aura which repels all matter." A girl, who is wearing one of the rings, walks up to Terry and gives him a rose while Bruce goes with Dr. Suzuki to see the specs on the rings. The girl introduces herself as Irene, and as they converse Terry is surprised when she tells him that she's never been outside the building.

Bruce looks over the specs and asks for a copy of them, but before he can get it, another doctor, Dr. Blades, arrives and angrily forbids it. Even when he learns who Bruce is, he refuses to allow it. Bruce says he only wanted to know whether the ISO-rings could be adapted into a weapons system - which proves to be the wrong thing to say. Dr. Blades angrily retorts, "Ah, so that's it. Well you can tell your Board of Directors that I will never participate in that kind of research. Not for you. Not for the Defense Department. Not for anyone." He then storms off.

That night, at Gotham Steel Ore a couple of thugs wait for the Repeller who crawls out of a vat of molten steel letting it harden then shattering it. He gives the criminals the Beta Sterillium in exchange for some credits. The female thug, Makeba, mentions that he only charged half as much for the Alpha Sterillium but he replies that the higher price is because of Batman. Makeba is concerned, as they still need the Gamma Isotope. Repeller assures her that they'll get it and if Batman gets in the way again, he'll kill him.

Later, Terry meets up with Dana at Cheezy Dan's and prattles on about Irene. Dana gets jealous and starts to walk away. Terry goes after her but he receives a call from Irene, which causes Dana to leave. Irene continues on and tells Terry that she's lost out in the city and when Terry asks if they let her out on her own, she tells him she escaped.

Irene and Terry go to the beach and Irene talks about how the only thing she can really experience is the sound. Terry tries to tell Irene about Dana but Irene suddenly notices that the rings are almost out of power and she must get back to the lab. Together, Terry and Irene sneak in but Dr. Blades is waiting for them. He bans Terry from the institution and grounds Irene.

Terry goes to Bruce and talks to him about Irene for a while. After that conversation, Bruce explains that Alpha Sterillium had been stolen from the University and that if both the Alpha and Beta Sterillium are combined with Gamma Sterillium it creates a powerful explosive. The best source for the Gamma Sterillium is the Blüdhaven Nuclear facility.

Meanwhile, Irene is left alone in the lab but notices that there's a bubble suit in her room. Donning the suit she calls Terry's house and gives Matt a message to tell Terry to meet her at the beach. Matt however doesn't really listen.

Unaware of Irene's location, Batman goes to the Power Plant and is ambushed by the Repeller. However, Batman throws a specialized batarang at him, which wraps him up in titanium ribbons. Unfortunately, the Repeller can break even them. Now free, the Repeller starts attacking with gravitational blasts finally succeeding in trapping Batman underneath rubble and pushing him towards the ocean. Batman is unable to escape and is buried in the ocean by the falling rubble. The Repeller believes Batman to be dead and leaves. Fortunately, Batman manages to escape.

Back at the research lab, Irene goes to get the Repeller rings but the Repeller arrives and removes his mask revealing himself to be Dr. Suzuki. Irene tries to hide but is discovered. Before Dr. Suzuki can deal with her, however, Dr. Blades comes in. Dr. Suzuki attacks him and explains that he figured out how to solve the power problems and decided it'd be more profitable to use the rings as a weapon than for medical purposes. He then hurls Dr. Blades out of the room and begins to crack Irene's helmet open but Batman arrives and tackles him. The two fight one another but Dr. Suzuki has the superior power and easily gains the upper hand. Fortunately, the fight forces Batman into a hangar, and Batman remembers Irene telling him the one thing that can get through the gravitational field: sound.

Dr. Suzuki flies in and repels Batman again. Batman hurls a batarang and hits the control panel, activating the turbines. Dr. Suzuki is unconcerned and keeps advancing. Bracing himself against the wall, Batman puts on a pair of headphones he snatched from the turbine operator and waits it out. Soon the turbine noise becomes deafening, and Dr. Suzuki is overwhelmed. Ironically, the field makes it impossible for him to put his own hands over his ears. In desperation, he shuts down the suit and is nearly sucked into the turbines. Batman manages to shut off the turbines and save Dr. Suzuki just in time.

With the ordeal over, Dr. Blades allows Irene to go out of the building. Terry is happy for her but tries to tell her about Dana. However, she introduces another friend, Larry, who is more than a friend to her. Ironically, Irene could never figure out when to tell Terry.