That’s a good thing. Movies and books are different beasts, and the former can only support so much exposition. The lack of an origin story didn’t stop audiences from falling in love with Ian McKellen’s Gandalf, who studied Tolkien himself in perfecting his award-winning performance, fixing himself in the hearts of millions of fans. Gandalf, the wise, mercurial, mysterious, and occasionally terrifying wizard is arguably more the face of the Lord of the Rings franchise than Frodo, its hero, or Aragorn, its long-lost king.

The real power of McKellen’s performance is that you believe wholeheartedly in Gandalf. But his role in the movies is still full of ambiguity. Is he, like, human, or what? What happened when he died? What’s the difference between Grey and White? What can wizards do, anyway? And who appointed Saruman president of wizards?

I can provide answers to all these questions, because I’m a giant Middle-earth nerd who thinks The Silmarillion is a more enjoyable read than The Lord of the Rings, and pillaged Tolkien’s Unfinished Tales to enhance the accuracy of my own Lord of the Rings Twitter account. Read on for everything you were always afraid to ask about everyone’s favorite weed-smoking magic grandpa.

Is Gandalf human? Can anyone be a wizard?

No. And also, no.

Gandalf is a divine spirit clothed in a mortal form. In Middle-earth parlance, he’s a creature known as a Maia (plural: Maiar). The Maiar are sort of like demigods, in that they serve a higher order of godlike beings, the Valar. And they’re sort of like angels, in that they are fully divine in origin (not half-human, like a lot of Greek demigods) and can change their form at will.

Other Maiar who appear in the Lord of the Rings movies include Saruman, Sauron, and the Balrog. (Yes, the monster and Gandalf are the same species.) Also, Elrond’s great-great grandmother is a Maia – his family is very complicated.

The Valar, Middle-earth’s cohort of caretaker gods, retreated from the world thousands of years before the time of The Lord of the Rings, and they took all of their Maiar with them. But, in the Third Age (that is, sometime after Isildur got his hands on the Ring in the prologue of the Jackson movies), Sauron began to amass power again. And since the Valar nearly had to destroy the world to stop Sauron the last time he rose to power, they decided to send some emissaries to Middle-earth to make sure he was kept in check this time around.

Image: New Line Cinema