Kotze is a fictional East German physicist hired by the criminal organisation SPECTRE to handle two stolen atomic bombs as part of their "Plan Omega" extortion scheme. He was given the SPECTRE designation "Number 5". The character appears in the 1961 Ian Fleming novel Thunderball and was subsequently adapted into the re-named character Ladislav Kutze, portrayed by George Pravda.
Kotze was was an East German physicist who had come over to the West five years before and had exchanged his secrets for a modest pension and retirement in Switzerland. During the events of Thunderball he travelled under the assumed identity of Emil Traut on his Swiss passport and was given an honorary SPECTRE designation "Number 5".
He was one of two scientists hired by SPECTRE (the other being Kandinsky) to study and adapt their two stolen atomic bombs; replacing their fuses with time mechanisms. In addition to his role as bomb-technician, Kotze's scientific knowledge was also used to produce suitably eroded coinage using acid, which was to be used as part of Largo's cover as a treasure hunter. Far from the relatively innocent pawn his later film counterpart was portrayed as, Kotze is involved with planning the murder of Domino Vitali and suggests that aqualung malfunction, combined with over-enthusiasm treasure-hunting, would be a realistic excuse for her death. He even sadistically suggests that she be thoroughly tortured for information and volunteers on the basis of his knowledge of electricity.
Physically, he is described as having a little thin figure with a furrowed brow and a "big egg-head" with pebble glasses. Largo viewed the scientist as a "depressing little man" and "a near hysteric", whose only value lasted so long as the bombs might need to be used. In a bid to minimize the associated risks of the physicist's excitable temperament, Largo planned to find some job in the engine room where he could be kept busy and, above all, out of sight. Largo's concerns about the man were proven justified, and he was quickly recognised by Felix Leiter whilst suspiciously loitering with Largo's men in a casino. Kotze survived the events of Thunderball, but was captured and told all he knew about SPECTRE.