Limbo

Limbo is a state of being that exists between life and death.

In May of 1998, Harry Potter allowed himself to be struck by a Killing Curse cast by lord Voldemort in an attempt to protect his friends and loved ones, and to destroy the piece of Voldemort's soul that resided within him. What neither he nor Voldemort realized, however, was that when Voldemort used Harry's blood in his resurrection in 1995, he unknowingly took Lily Potter's magical protection of Harry into himself as well.

Harry awoke to find himself lying in a formless mist. As the mist began to take shape into King's Cross Station, Harry saw a stunted, whimpering child-like form lying on the ground, to which he felt both pity and revulsion. He also saw Albus Dumbledore, his deceased mentor, and the two had a long talk in which Dumbledore answered many of Harry's questions, and told him that he was not actually dead. As a soul that was whole and complete, Harry was given the choice to return to the world of the living to finally stop Voldemort, or to board a train and "go on".

With the destruction of all of his Horcruxes, when Voldemort's Killing Curse rebounded and finally ended his life once and for all, his broken and mangled soul was forced to exist in the stunted form Harry saw in King's Cross, unable to move on or return as a ghost.

Appearances

 * Harry Potter and the Deathly Hallows