Even after he's won the final key, Parzival's challenge isn't over. The last test comes when Anorak (Halliday's OASIS avatar) offers Parzival a contract, telling him all he has to do is sign and the OASIS will be his. Parzival, who's spent years studying not only Halliday's pop culture interests, but also the details of his private life, is wary.
In Halliday's memories, Parzival found a common thread that went beyond his failure to win Kira's heart. While he may have regretted not taking a bigger chance with Kira, Halliday's greatest regret was his acrimonious split from Morrow. When the pair split professionally, Halliday presented Morrow with a contract forcing him to turn over his stake in the company they built together. Halliday never got over the way he left things with his friend. Parzival recognizes this, sees the similarities between his contract and the one Halliday signed, and refuses Anorak's offer.
That's when, in a moment that mirrors the ending of Willy Wonka and the Chocolate Factory, Anorak reveals that the contract was a moral test, and that Parzival passed. The castle transforms into a child's bedroom, and Halliday appears as a virtual version of himself, presting Parzival with both a big red button that will wipe the OASIS clean and a golden egg. As the egg flickers in his hands, Parzival's real-world friends can see its glow even outside of the OASIS. That's when Halliday's real lesson becomes clear.
