What is it like not to be able to communicate with others? NOVA explores the severest of speech disabilities with Dick Boydell - born with cerebral palsy, confined to a wheel chair and unable for 30 years to say more than "yes" or "no" and investigates some of the new technology that gives the speechless a 'voice'.

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?