The TARDIS lands on the jungle planet Deva Loka, where an Earth expedition has been sent to study the Kinda, a tribe of primitive people. Three team members have already vanished. Are the Kinda as primitive as they seem?
Sanders meets Panna and Karuna who leave a lasting impression on him, while the Dukkha does the same on Tegan. When Hindle's breakdown begins, the Doctor and Todd are in danger.