Kipton and the Monkey's Uncle — Charles Louis Fontenay

Bored with daily life on the Pile, Kipton gladly accepts Nikolai's invitation to spend some vacation with his family at West Mars, his family's estate outpost a quarter of the way around Mars. Nikolai is of Russian origin. She goes with Dr. Burundi, who was to attend a scientific conference to examine a huge diamond "find" that could be an ancient artifact, proof that Mars had been inhabited.

Just as the conference begins, the diamond mysteriously vanishes. Braving a horrible floating head in her room at night, Kipton's attention to seemingly unrelated details solves the case.