Who really is Dieter in Matthias Schweighöfer’s Army of Thieves - and how does it factor into Zack Snyder’s Army of the Dead? The prequel movie Army of Thieves sets up a detailed backstory for Dieter’s (Schweighöfer) character, along with the string of events that lead up to his involvement in the Vegas heist in Snyder’s film. By positioning Dieter front and center, audiences are able to connect deeper to the character on an emotional level, which grants more weight to Dieter's eventual fate in Army of the Dead.
Army of Thieves opens with an optimistic Dieter filming a YouTube video in Germany taking a shot at opening Hans Wagner’s Ring Cycle, a series of high-craftsmanship safes that are deemed almost impossible to crack. Not being able to garner any views or engagement, he goes on to live out the monotony of his everyday life as a banker, although that profession neither challenges nor excites him. Dieter’s inner world is fleshed out gradually, along with his fear of zombies that manifest as nightmares, although it might also function as foreshadowing or a prophecy of his eventual fate with them in the near future.
Before going by the name Dieter, the young master safecracker was born Sebastian Schlencht-Wohnert but was always passionate about safecracking from a formative age. When approached by Army of Thieves' international jewelry thief Gwendoline (Nathalie Emmanuel) for recruitment in a high-stakes heist, Sebastian initially hesitates, as prior to this, he had never engaged in any form of criminal activity. However, exhausted by the predictable patterns of his life, and moved by the desire to unlock the sacred mysteries of Wagner’s safe, he joins in the crew that includes Rolph (Guz Khan), Brad Cage (Stuart Martin), and Korina (Ruby O. Fee). On learning that Brad Cage is, in fact, not a real name during a conversation with Gwendoline, Sebastian launches into his own backstory, and how he used to have a heroic alter-ego as a child.
Due to his differed interests from other children of his age, Sebastian spent all of his time cracking safes and learning the delicate craft, which left him rather alienated and lonely in the process. In order to combat the feeling that he never really fit into the world, Sebastian started drawing a comic book about a master safecracker and explorer named Ludwig Dieter, a heroic persona he could seek refuge in and relate to. Gwendoline finds this name charming and easier to pronounce, which leads her to having Sebastian’s passport created with the name of Ludwig Dieter, explaining his identity in Army of the Dead.
After coming to America, Dieter names his shop after Gwendoline and spends his time honing his skills, right until he is approached by Scott (Dave Bautista) and Maria (Ana De La Reguera) for cracking the Götterdämmerung in Army of the Dead. As the generally timid Dieter heroically saves Vanderohe’s life whilst being dragged away by Zeus offscreen, this completes his transformation from being a nobody in Army of Thieves to being a heroic character who sacrifices himself in the end. As it is entirely possible that Dieter is still alive, a new cycle of rebirth could prompt him to cross paths with Gwendoline again, and possibly put an end to the zombie apocalypse occurring in the Army of the Dead universe.