Spike didn't want to go to the Pizzeria, Spike didn't want to get murdered either, but life as a funny way of ending on you.
Spike ends up getting murdered by a Pony in a Golden Bonnie suit and his body is merged with that of the Puppet animatronic so as to avoid any evidence, this results in Spike's restless soul merging with the Puppet and becoming one, shame all his memories jumped ship at the same time, Now it's up to the Puppet to figure out what happened, and make sure it doesn't happen again, a task he failes at drastically.

This Story has a Sequal The Nightmare