|First appearance||The City of Gold and Lead|
|Portrayed by||Robin Hayter|
Julius, the leader of the free men, began a programme for training many of the young boys and girls for annual games where the winners were taken to the Tripod City, so that some might learn important information about the Tripods and bring back the information to the free men. Fritz excelled in sprinting and displayed discipline, which led Julius to choose him as one of the contestants leaving to compete.
Fritz, Will and Beanpole traveled to the ship named Erlkonig, where they were kept in line by the captain Ulf. While Fritz remained dutiful, Will and Beanpole broke the rules by leaving the ship to find Ulf after he had been gone too long at a port. Ulf returned to the ship, having heard that someone matching the description of Will had been causing trouble at the port. He and Fritz left without Will or Beanpole.
Fritz was successfully taken to the games, though Will and Beanpole also managed to follow later by their own means. Although the competition at the games was tough, Fritz was able to win at his own sport and was chosen to be taken to serve the Tripods. Will was also chosen, but Beanpole failed. Fritz and Will were lifted into Tripods and began the journey to the European Tripod City.
In the city, Fritz and Will discovered that the gravity was much stronger there and the air was hot and humid. They were chosen by different Masters and personal slaves, revealing that aliens from another planet were the force behind the Tripods.
Fritz was efficient with his studies of the city although he had a harsh Master who enjoyed abusing him. He found out that the city gets its energy from the Pool of Fire and that there are several underground tunnels for water circulation. Later, when Will accidentally killed his Master, Fritz helped Will escape through one of these tunnels, though he stayed behind himself to help establish Will's alibi.
Fritz stayed in the Tripod City for some time before escaping the same way Will had. He got sick on his way to the White Mountains, but was taken care of by a strange woman. Eventually, Fritz was able to return to the White Mountains, where he was immediately paired up with Will on a journey to recruit young, uncapped boys and girls from the south-east. On their journey, they visited the Middle East and Russia, where they saw a Tripod chase take place.
The pair returned to Europe and settled in a castle with other freemen, including Julius and Beanpole. They were introduced to a plan to trap and Tripod and catch a live Master. The plan was put into motion and after some initial struggle, a Master was caught alive. Fritz and Will would often visit the Master Ruki in his cell to gather information.
When it was discovered that Masters are extremely vulnerable to alcohol, another plan was formulated. Fritz would lead a group of freemen, including Will, into the European Tripod City and create alcohol from the available supplies to contaminate the Masters' water supply. Other groups in Asia and America would do the same to the respective cities. Fritz led his group successfully into the city through the water vent he had escaped through, and was also successful in contaminating the water supply with his allies.
The Masters were soon knocked out by the alcohol, which caused their slaves to fall into depressing. Fritz prevented them from committing mass suicide by lying that the Masters were just sleeping and would awake soon to continue their activities. Fritz led his team to the Pool of Fire, where they managed to shut it down.
Next, the team had to find a way to destroy the dome of the city to poison the unconscious Masters with Earth air. This was done by climbing up a ramp to a chamber with tight doors preventing the airs of the city and Earth from mixing. The boys destroyed the doors, which caused a change in pressure that shattered the dome, effectively killing the Masters. The boys reignited the Pool of Fire to be able to open the doors, which were then used to escape the city.
Months of inactivity followed for Fritz and Will. They would occasionally fly with air balloons made by Beanpole for fun, but otherwise they had nothing to do. However, the attack on the American Tripod City had failed, and the contingency plan of using newly discovered airplanes had also met failure. Fritz led another team of boys to America to bomb the city from air balloons. On the way he had to lecture Will about his temper.
The final attack on the city seemed like it was going to fail at first, because the bombs thrown from the air balloons ricocheted from the dome's surface and exploded without damaging it. However, Henry managed to destroy the dome by sacrificing himself.
Fritz spent time farming after Earth was free. He was reunited with Will and Beanpole when they visited the Conference of Man. They witnessed the leaders of the world and decided to dedicate their lives to promoting peace among nations.
Fritz has a distinctive personality, being serious and dutiful. He is often described as the "emotionless German", although he does show more emotion after getting to know Will better. Fritz is resourceful and has good discipline. He values the safety of others before his own, as demonstrated frequently during his missions in the Tripod City. His sense of duty led him to be respected by Julius in particular, and later by Will.
- Episode 14: The White Mountains: 2090 AD
- Episode 15: Travel
- Episode 16: Will Is Arrested (Mentioned only)
- Episode 17: Help From Friends
- Episode 18: City of Gold
- Episode 19: Will Is Made a Slave
- Episode 20: Hunt for Eloise
- Episode 21: The City of Gold
- Episode 22: Blessings of the Cognosc
- Episode 23: The Cognosc Departs
- Episode 24: Escape From the City of Gold (Mentioned only)
- Episode 25: The Forest of Death (Mentioned only)