Bem

The Enterprise welcomes Commander Ari bn Bem of Pandro, a newly contacted world, as an official observer. During a survey of the planet Delta Theta III, Bem joins the landing party and soon proves far more trouble than any guest should be. His body can separate into parts that act independently, and he quietly makes off with the landing party's equipment, insisting it is all part of his study of the humans. Bem is repeatedly captured by the planet's primitive natives, and Kirk's party falls into their hands too while trying to rescue him. Then a powerful, bodiless being reveals itself as the guardian of the natives, angry that outsiders are meddling with the people in its care. Confronted with his own arrogance, Bem humbly asks to be corrected. The entity recognises Kirk's sense of responsibility and orders the visitors to leave, and back aboard the Enterprise Kirk places the planet under quarantine.