wears glasses. Depending on the case, Bob's father is a sports writer, business journalist, or political journalist, and occasionally helps The Three Investigators in some of their cases. Early in the series, Bob is hampered physically by a leg brace he wore, due to multiple fractures suffered when he rolled down a hill. This handicap relegated him to a more studious and less physical involvement. Bob works part-time in the local library, suiting his role as data collector. Bob also serves as the clue-bearer for many of the adventures, because of his research at the library. Bob's leg brace is removed between the end of Whispering Mummy and the beginning of Green Ghost. Headquarters The office of the Three Investigators is a house trailer, hidden among the piles of junk at the edge of Uncle Titus' junkyard. The house trailer has multiple secret exits, a small lab, a darkroom, and an office with a phone, typewriter, and reference works. Many other utensils, such as a tape recorder or a periscope, were built by Jupiter who used spare parts found in the scrapyard. Copyright dispute Initial position The series was invented by American writer Robert Arthur in the US in 1964. Arthur sold the international exploitation rights to the publishing house Random House. However, the copyright remained with him. The contract included the rights to publish books, films, comics and mechanical sound reproduction. Since there was no significant audio book market at that time, it is legally not clearly determinable and therefore doubtful whether this "mechanical sound reproduction" describes the medium of audio books or radio plays as they exist now. The Franckh-Kosmos publisher of Random House acquired the German-speaking exploitation rights in 1968. The label EUROPA received the rights to the audio version of the series as part of the sublicense partners of the Kosmos Verlag. After Robert Arthur's death in 1969, the copyrights were given to the University of Michigan. In his will, Arthur declared that "all rights, legal titles and stakes, [he] owned by the time of [his] death, concerning all published books, short stories, plays or unpublished manuscripts, including all issued copyright claims, just as all rights for license fees and subsidiary rights, as it is specified in [his] contracts with publishers" were to be given to the University of Michigan. Since then Random House had been paying royalties to the university, but they stopped doing so