The Hades Shuttle Service Courtesy Phone, installed sometime between 966-1067 GUE at the Underground Underground station's entrance to Hades, was the modern method to summoning Charon in order to bear the recently deceased across the River Styx (it is unknown as to whether any of the other entrances to Hades had courtesy phones). Just before 1067, this service underwent a retro-fitting to insure full ease of abuse, customer dissatisfaction, and user-unfriendliness while inefficiently bringing the recently deceased to their final destination. Before crossing, a "few simple questions" needed to be answered using the touch tone pad. Because of the nature of these questions and the lineup of frustrated customers, the Hades Shuttle Service installed a Courtesy Phone Hint Line shortly thereafter. If all the questions were answered correctly, a shuttle would be along shortly for transportation to Hades.

While the listing of questions varies, the following helps to explain the difficulty in gaining entrance to the underworld. It was not the chooseable answers that were confounding:

but how to use them:

Though some intelluctual enchanters have found the KENDALL spell to be vary helpful in bypassing the nastiness of this service.

SOURCE(S): Zork:Grand Inquisitor