What is changing of the guard twilight zone?

"Changing of the Guard" is an episode from the first season of the television series "The Twilight Zone". It originally aired on June 1, 1962. The episode follows the story of Professor Ellis Fowler, a longtime teacher at a New England college who is forced into retirement due to his advancing age and declining health.

Feeling depressed and alone, Fowler begins to contemplate suicide. However, he is visited by the ghosts of his former students who remind him of the impact he had on their lives. This leads Fowler to reconsider his perspective and find a new purpose in life.

The episode is known for its emotional depth and exploration of themes such as aging and legacy. It is considered one of the finest episodes of the series and was praised for its poignant ending.