Worried about the Old Silurian's growing friendship with the Doctor, the Young Silurian has the scientist infect Baker with a virus and then release him.
Did You Know?
The color master tape of this episode was wiped by the BBC in the 1970s and the BBC only held a 16mm black and white telerecording. The episode remained only in black in white until the 1990s, when the color signal from a domestic NTSC recording and the black and white telerecording were used to create a new color master on D3 digital tape. See more
When Major Baker gets up off the cave floor, the large rock on which he was lying wobbles violently, revealing it to be made of a lightweight material. See more
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