Sometimes, though, Infocom threw in puzzles just for the humor of it—if the user never ran into these, they could still finish the game. But discovering these early Easter Eggs was satisfying for some fans of the games. For example, one popular Easter egg was in the "Enchanter" game, which involves collecting magic spells to use in accomplishing the quest. One of these is a summoning spell, which the player needs to use to summon certain characters at different parts of the game. At one point the game mentions the "Implementers" who were responsible for creating the land of Zork. If the player tries to summon the Implementers, the game produces a vision of Dave Lebling and Marc Blank at their computers, surprised at this "bug" in the game and working feverishly to fix it.