Unstoffe was the accomplice of Garron, tricking people into buying planets by making them believe they contained the valuable mineral jethrik. He was working with him during their con of the Graff Vynda-K.
Unstoffe was Garron's younger partner and had been working with him for a long time. Despite Garron's influence, Unstoffe was more sympathetic to others. He told Binro — a Ribosian who showed him kindness when he tried to escape Shrieve's — that his theories about other worlds were accurate to thank him for his assistance. When Binro was killed by the Graff, Unsoffe became depressed.
He was later reunited with Garron, the Fourth Doctor and Romana I. When the two Time Lords left the planet, Unstoffe remained with Garron who had previously claimed that they were going to retire. He and Garron then left Ribos in the Graff's spaceship, which was full of eighteen year's of plunder. (TV: The Ribos Operation)
Unstoffe was a con artist but he did care about other people which was shown by his friendship with Binro and his loyalty to Garron. He was willing to stand up to Garron and even called him a hypocrite. (TV: The Ribos Operation)