Kishin Corps' top agents, Bareiho, Daisaku, Kimiko and Taishi, attempt to kidnap Hans Lingelle, the Nazi officer in charge of special weapons development and other general evil, from an embassy party in Tunisia in July 1943. Agents of the Kanto army evacuate Lingelle and bring him to meet with Colonel Shinkai. Lingelle informs Shinkai that the Nazis will no longer be collaborating with them on the development of fighting mecha. He hints at newer, even greater weapons within their reach and a possible alliance with the aliens being negotiated by the occult-obsessed Fuhrer.

Thus snubbed, Shinkai is as unpleasantly shocked as the Kishin Corps when Lingelle arrives during a pitched battle where a Kishin plane carrying top scientists and a certain violin playing white-haired Swiss physicist is pinned down by enemy fire as it tries to escape from Europe to America. Later. The Nazis have a new mecha, Panzer Knight (a really big mecha that doesn't fully work).

After the battle Shinkai recruits a special new agent to help solve his severe case of mecha envy by reacquiring the control module that Eva Braun now studies.

"Panzer Knight Part II" brings Taishi face to face with his own past failings as he pursues the agent who stole the control module and wounded Eva Braun. The thief is a desperate and hardened young man, whom Taishi follows back to a familiar ragtag group of war orphans. Two years previous they were betrayed, attacked, and left for dead. Taishi's old compatriot Jack, now a freelance saboteur, blames Taishi for the Kanto army raid that killed their fellow orphans and feels no remorse now about taking money from the Kanto army to steal the module.

Aliens attack just as the Kanto thugs flee with the control module Jack brought them; and Taishi earns Jack's forgiveness by shepherding his brood of helpless waifs to relative safety. Taishi promises to return this time and take care of his friends . . . after just one more frenzied three-sided battle.

With the action now unfolding in the chronological and geographical center of WWII, the Nazis come onscreen (they scarcely appeared in the first three episodes) and replace the Kanto army as the primary villains. Lt. Fujishima, Shinkai's aide, has been used throughout the series to humanize the Kanto army. She serves reluctantly and loves her homeland, but despises the Nazis and, in fact, has been quite literally taken advantage of by Lingelle in particular. In contrast, Lingelle and the Nazis, portrayed as fellow travelers with the aliens and perhaps practitioners of black magic besides, quite naturally fit the role of inhuman, unadulterated evil.

Struggles between good and evil are a dime a dozen. Introducing new enemies and complicating the roles of old ones expands the plot into a struggle between good (Kishin Corps), evil (Nazis), misguided nationalism (Fujishima) and the hostile unknown (aliens). This more complicated struggle suits the thematic concerns of "Geo-Armor," which also grows more explicitly entangled with history.

In episode three Eva Braun and Bill Saguro voiced two sides of a debate about the ethics of science, with Taishi speaking for Maria in absentia. In "Panzer Knight" we see Maria Braun making music and chatting with Albert Einstein who historically represented the humanist perspective that Taishi had assigned to Maria. Depicting them together concretely connects the examination of technological ethics in "Geo-Armor" to its historical analog.

Einstein raises several new issues when he reveals that he has provided the Americans with the recipe for a super-bomb and when he speaks about the injustice of, "Men sacrificing themselves for nations when nations ought to be serving the interests of mankind."

Jack also speaks personally about this injustice when he says, "The war is being fought by adults and we're the ones paying the price." Meanwhile Eva fears that Einstein's bomb will, "Make scientists the enemies of humanity."

The potential arrival of the American bomb also complicates Kishin Corps' mission, since they must now defeat the evil enemies (within a specific time frame) without allowing their own technology to become an even greater terror. These new concerns also transform the ethical debate from a simple question of whether or not scientists are responsible for the consequences of their work into a discussion as multifaceted as the plot.

The nature of the much-sought-after control module itself is clarified in these episodes and helps build "Geo-Armor's" thematic concerns. The control modules have the ability to make anything run more efficiently and more controllably. Without them, controlling the complex mecha would be impossible for a human pilot. When Lingelle reveals the Nazi plan to mass-produce mecha, we learn that only the most mentally and physically gifted can pilot them. Such is the challenge of interfacing with a control module. In fact each pilot put into the Panzer Knight is corrupted and consumed - often before they can complete a battle. In Kishin Corps, only the select few; Bareiho, Daisaku and Kimihiko, can survive piloting the three Kishin mecha.

The propensity of Nazi pilots to hemorrhage when controlling their monstrously large and invincible super-weapon is an undeniably convenient plot device for the survival of Kishin Corps. However, it makes sense within the logic of the series' metaphors. The control modules are now defined as a piece of technology that works properly only when used by the virtuous, and thus becomes a metaphor for technology in general: Under the control of the evil and misguided they become self-destructive. Used by the heroic and virtuous (Bareiho), the control modules (meaning technology) are the best hope for defending humanity against evil and the unknown. Thus, because of the nature of the modules, the coming battle between good and evil will test the character, as well as the might, of our heroes.