The Visitor (1995)
Another example of Star Trek using time-travel tropes to twist an emotional dagger in your heart, this Deep Space Nine classic hinges on the relationship between Sisko and his son Jake, a tragic story of fatherhood as an elderly, retired Jake tells a tale of how a subspace accident aboard the Defiant caused his father to begin slipping in and out of “time,” watching his son grow old without him like a temporal ghost. Bring tissues when you watch.
