Sapphire & Steel (1979)

Season 3: Episode 2

Rothwyn and Eldred, the couple living inside the space capsule, begin to realize they might be in serious danger when they cannot make contact with fellow study groups or with their superiors. The evil creature inside the capsule begins an attack by using time to transform the couple's infant into a grown man. As Sapphire and Steel deepen their investigation, Sapphire discovers that the mechanism which transported the capsule is no ordinary machine.