The next stop of the 999 was the Insect Planet. It used to be paradise for insects before the humans colonization, and the Conductor warned Tetsuro and Maetel of the recent murders that have been taking place. Maetel and Tetsuro came a cross a man murdered, and his caged insects were released. They went to the house of Futoshi, Keiko, and their family, where Tetsuro saw the murderer ran into, but they did not find the perpetrator. In the following morning, Keiko met Tetsuro, and pleaded him to become an insect with her. A group of insect people appeared and tried to kidnap Tetsuro, but Maetel appeared and saved him. They returned to Keiko's home to find that she was transformed into an insect. She was, indeed, the one behind the recent killings. Keiko asked everybody to leave the house, blew up her room and killed herself.
Des avertissements sur des meurtres mystérieux ont lieu sur la Planète des Insectes. Après leur arrivée, Tetsuro et Maetel tombent sur la scène du meurtre d'un homme d'affaires. Il semble que la clé des meurtres soit une fille nommée Keiko qui soutient la cause des insectes et s'est rangée de leur côté. Elle demande alors rapidement à Tetsuro s'il accepterait de devenir un homme-insecte pour aider à sauver les insectes de la planète. Ensuite, de très petits hommes-insectes apparaissent devant Tetsuro.
