You misinterpret. There were three episodes.
First episode, he shows up at Sabrina's Gym, gets royally fucked, and Sabrina's Dad points him towards Lavender Town.
Second episode, he goes to the Pokemon Tower, meets a Gastly, Haunter, and Gengar, dies, comes back to life, and goes back to Saffron City with a Haunter.
Third Episode, Haunter is a no-show when the battle starts, but shows up in time to make Sabrina laugh and miraculously bring back her humanity.