Star Trek: The Original Series: Vol. 19: Episodes 37 & 38: The Changeling / The Apple

The Changeling: (Episode 37)
While investigating the destruction of the Malurian System and its four billion inhabitants, Kirk discovers "Nomad," a robotic space probe gone wild.Kirk beams it aboard the U.S.S. Enterprise, only to have it kill Scotty and erase Uhura's mind.It's next target -- Earth.Can Kirk find a way to stop this deadly machine?

The Apple (Episode 38)
On Gamma Trianguli VI, Kirk and a landing party are plagued by poisonous plants, exploding rocks and attacks by lightning.They learn from the childlike natives that the planet is ruled by "Vaal," an all-seeing "god" which interprets Kirk's presence as a threat to the stability of the culture.To preserve this simplistic society, Vaal plans to destroy Kirk and the U.S.S. Enterprise.