Wesley is still living with the fallout on his mind in his last appearance in “Journey's End,” where it's clear from the moment that he returns to the Enterprise that he is unsettled with his role in Starfleet Academy and wants a new challenge.

What episode does Wesley Crusher come back?

Episode no. "Journey's End" is the 172nd episode of the American science fiction television series Star Trek: The Next Generation, and is the 20th episode of the seventh season.

Why did Wesley Crusher leave the show?

According to Wheaton's post, he was cast in 1989's Valmont, and needed to be written out of a single Next Generation episode to accommodate the movie shoot in France.