We've uncovered another trailer for Harry Potter and the Half-Blood Prince.

In the movie, which opens on July 17, Harry Potter begins his sixth year at Hogwarts School of Witchcraft and Wizardry - and discovers an old book marked mysteriously with the words, “This book is the property of the Half-Blood Prince.”

From there, Harry learns more about Lord Voldemort’s dark past.

In the video below, we're treated never-before-seen footage of Professor McGonagall, Narcissa Malfoy, Luna Lovegood...