Kit Harington explained why he agreed to play Gilderoy Lockhart in the Harry Potter series

Kit Harington, known for playing Jon Snow in Game of Thrones, opened up about his decision to join the HBO series based on the Harry Potter books.

The actor appeared on Today, where he explained that the idea of a detailed adaptation of the novels drew him in. Harington will play Gilderoy Lockhart in the second season, based on Harry Potter and the Chamber of Secrets.

He replaced Nicholas Hoult in the role, who left the production due to a scheduling conflict. The character isn't new territory for Harington, since he voiced Lockhart last year in the Harry Potter: The Full-Cast Audio Editions audiobooks.

Kit Harington said:

When I knew this was happening as a series, I thought it was the best idea. I love the films, but with this, they can really explore the books at their fullest, and for a book nerd like me, that was a really great idea.

His point holds up given how much the 2002 film adaptation cut out. Several of Lockhart's scenes were among the casualties, back when Kenneth Branagh played the role.

The book goes into far more detail about just how self-indulgent and grandiose the Defense Against the Dark Arts teacher gets, constantly inserting himself into other classes and situations that don't concern him.

One of the missing scenes involves his ridiculous Valentine's Day breakfast, where he turns the Great Hall a garish shade of pink and brings in dwarves dressed as cupids carrying harps. The series format gives enough screen time to bring back details like these.

The first season, Harry Potter and the Philosopher's Stone, premieres on HBO in December.