A humaniform robot—indeed, the first robot to be given realistic human form—Daneel is designed by Auroran roboticists Dr. Roj Nemennuh Sarton and Dr. Han Fastolfe, but constructed on Earth by Sarton, There, his appearance is so convincing that he is teamed with the protagonist, plainclothesman Elijah Baley, in solving homicides. Sarton is the first victim and the case, depicted in The Caves of Steel, is mentioned in flashbacks in this novel, as is their next meeting in The Naked Sun on the planet Solaria, investigating the murder of Rikainne Delmarre, husband of Gladia Delmarre/Solaria. In The Robots of Dawn, they team up to investigate the murder—roboticide—of Daneel's lookalike, R. Jander Panell.