4702 The Final Challenge is a Harry Potter set released in the year 2001. It contains one spiderweb, the Mirror of the Erised, Harry Potter, and Professor Quirrell, who has Voldemort's face on the other side of his head.

The mirror has a lenticular sticker that flickers between Harry with and without the Philospher's Stone. The actual stone, a ruby red jewel piece, can be revealed when the door is revolved to the other side. Above are two torches, a bat, and a black owl. The idea is to have Harry fight Quirrell and find the stone. The set is designed to fit between 4730 The Chamber of Secrets and 4704 The Chamber of Winged Keys, with 4751 Harry and the Marauder's Map on top of the set.

The minifigures included are Harry Potter and Professor Quirrell. Quirrell has a double-sided head, one with his normal head and the other with Lord Voldemort's features. He is noticeably the first minifigure to ever have this feature.

In 1992, Harry Potter, Ron Weasley and Hermione Granger set out to stop Lord Voldemort from stealing the Philosopher's Stone from within Hogwarts. Harry entered the final room alone, and confronted Professor Quirrel, whose body was also playing host to Voldemort. Here, Harry looked into the Mirror of Erised and was given the Phillospher's Stone by the mirror, magically placing it in his pocket. Quirrel then revealed Lord Voldemort behind his turban and attempted to attack Harry. However, Harry was protected (Voldemort was unable to touch Harry due to his mother's magic) and Quirrel was destroyed when he grabbed Harry.