The Tomb of the Unknown Implementor, within the gates of Hades, is the anteroom to the Crypt of the Implementors in its north wall. The crypt entrance is surrounded by four severed heads of fallen Implementors of unknown identity. Although they are dead, they foresaw that some cretin would tamper with their remains. Therefore, they took steps to punish such actions with a curse that would place the violator's head upon a like pole. Above the door is the cryptic inscription "Feel Free."

Upon entering the tomb, one is greeted by a hollow voice that says, "That's not a bug, it's a feature!" The remainder of the chamber contains alien-like relics evidently produced by the Implementors during their long struggle to win totally, such as bottles made out of magic glass that when broken disappear immediately, and deteriorating stacks of line-printer output.

While this chamber is almost a mirror image of the Tomb of the Twelve Flatheads, most archeologists presume this crypt is the original.