School vacation has never seemed longer. 'Potter' heads who've been breathlessly waiting two years since the last movie from the mega-popular franchise can finally exhale -- Harry, Ron, Hermione and their classmates are back for year 6 of Hogwarts training in 'Harry Potter and the Half-Blood Prince' (opens July 15), which is shaping up to be the most romantic -- and of course, mature -- installment yet.

We visited the 500,000-square foot Leavesden Film Studios in rural London (imagine an interconnecting complex of 15 Home Depots, plus dazzling exterior sets) to see where Daniel Radcliffe, Rupert Grint and Emma Watson have spent the better part of the last decade of their lives -- and to get the scoop on their latest 'Potter' adventure. Keep reading for a sneak peek from the set of 'Half-Blood Prince.'