An officer in the Wehrmacht Heer (Nazi Germany's regular armed forces), Heller doesn't appear until close to the end of the film. He and his men, including two sergeants, are dropped off by a submarine off the coast of England near Ms. Price's house. They quickly take her and the children hostage, with Heller using Ms. Price's house as a base of operations. He explained that their mission was to cause mischief, mayhem and sabotage to prove to the British government that Germany could land troops whenever and wherever they wished, in an effort to bully them into surrendering. Ms. Price attempted to turn him into a rabbit, but she forgot the words to the spell. Annoyed, Heller ordered her and the children taken away and locked up in the armory museum.
This proved to be a mistake. Ms. Price brings all the suits of armor in the museum to life, and sends them to attack the Nazi Germans. Upon seeing this approaching army through his binoculars, Heller couldn't believe his eyes. His main sergeant, a superstitious man, became afraid and said Ms. Price was a witch. An annoyed Heller fired back that there was no such as a witch. He insisted it was some kind of trick. "A pretty good trick!" insisted the sergeant. Heller ordered his men to fire at the approaching knights. The gunfire did no good, and after a comical battle, the Nazi German soldiers fled back to the submarine.
Heller insisted they stay and fight, reminding them they were German soldiers, but turned and fled, himself, when confronted by a huge suit of armor wielding a gigantic axe. A short while later, he and his superstitious sergeant encountered Ms. Price again. "The witch!" cried Heller, terrified, and his sergeant sarcastically albeit fearfully reminded him he'd said witches didn't exist. Heller made no reply. Ms. Price told him to leave England and go home, and that the British people weren't as easy to beat as the Nazis had thought. Requiring no further persuasion, Heller joined his men and returning to the waiting submarine and fleeing back across the Channel.
Heller was apparently not as purely evil as many of his peers in the German military. At the very least he was an extremely pragmatic man who never committed evil acts for evil's sake. For example he never harmed Ms. Price or the children, and, when they became a hindrance to his plans, he had them locked away instead of killing them, showing him to be a man who believed civilians shouldn't be harmed in times of war. Despite this, he was an impatient and short-tempered man and extremely verbally abusive, raising his voice and yelling at both Ms. Price and the children, especially when they defied him.
In addition, he was arrogant, thinking little of British people's fighting spirit in the face of Germany's military might.
He was an extremely brave man to the point of being foolhardy, and expected the same from his subordinates. When they ran in fear, he became angry at them. Only when his own life was immediately in danger did Heller finally turn and run, too.
Prior to the incident with the living suits of armor, he was a very skeptical person. He dismissed the idea of magic. However, he wasn't stupid, and for all his reckless bravery and skepticism, Heller eventually came to truly believe Ms. Price was a witch just as his sergeant had said. This marks him as a man who can't ignore the evidence staring him in the face, regardless of his prior beliefs.
- His weapon is a Walther P38, which he carries and even unholsters, but never actually fires.
- He has been awarded the Iron Cross 1st Class and the Iron Cross 2nd Class, both medals for battlefield heroism and bravery.