The Department of Mysteries is, unsurprisingly, pretty damn mysterious: a top-secret Ministry of Magic department dedicated to the queries of creation, to the study of life, magic and death. We got a glimpse of it, of course, in Harry Potter and the Order of the Phoenix, when Harry and co got lost amid its peculiarities. But that was only a glimpse, a tantalising tease that offered us just enough to be intrigued, but left us with more questions than answers. Questions like…

Who works there, and what do they do?

The work of the Department of Mysteries is so sensitive that its employees are known as Unspeakables: wizards and witches who are forbidden from disclosing any details about their job, the department they work in or the work they do. As such, little is known about the specifics of their jobs. Yet it is known that the employees must study some of the subjects of the rooms that Harry and his friends find themselves in when they visit the Department. These include, love, death, and, well, something to do with brains…

What is the purpose of the prophecies?

First, let’s tackle one of the department’s most well-known elements: prophecy. Prophecies, as you know, are predictions of the future made by Seers, which are then somehow recorded into spun-glass spheres and stored in the Department of Mysteries’ Hall of Prophecy.

But why? Why are these prophecies collected, stored and then hidden away from the only people who can pick them off the shelf – the person that the prophecy is about? Or is it because wizards consider prophecies an unnatural tampering of fate? Or is it something else?

What’s the deal with the brains?

All we’ve seen of the Department of Mysteries are snapshots – strange, enigmatic glimpses of a bigger picture. The most striking of which was a tank full of aggressive brains, swimming in green solution, trailed by deadly tendrils. It’s implied that the brains are used to study thought, but how, and why? And what about the brains themselves: are they a new entity, or did they used to belong to someone? And if so, who? And just why are they so angry anyway? It’s not Ron’s fault that they’re big stupid brains.

How do you make a Time-Turner?

The Time Room is adorned with clocks, lined with Time-Turners, and features a bell-jar in which a bird hatches, lives and dies on a loop. It is, of course, the room dedicated to the study of time, and is speculated to be where Time-Turners originated from. It’s known, for example, that the Department of Mysteries experimented with time travel in the 19th century, with Unspeakable Eloise Mintumble managing to break several of its laws. It’s assumed that such instances made the Time-Turners taboo among wizards, forcing the Department of Mysteries to restrict the technology to that room. Just think of the magic involved.

What do wizards know about space?

The Harry Potter series tackles many things, but what lies beyond the stars is not one of them. Unless you count the centaurs of the Forbidden Forest saying, ‘Mars is bright tonight’. Hence the intrigue of the Space Chamber, a dark room full of floating replica planets, where wizards study the mysteries of outer space. But what does that entail, exactly? Is there magic in the heavens? Do wizards know of alien life on other planets? And are there aliens wizards too?

All we know is that we want a sci-fi Harry Potter spin-off immediately.

What is love?

‘There is a room in the Department of Mysteries that is kept locked at all times,’ said Albus Dumbledore. ‘It contains a force that is at once more wonderful and more terrible than death, than human intelligence, than the forces of nature. It is also, perhaps, the most mysterious of the many subjects for study that reside there.’ Harry Potter and the Order of the Phoenix

He is talking, of course, about love, which is studied in the Department of Mysteries’ uber-secret room, the Love Chamber. Obviously, little is known about the actual room itself, but it is rumoured to feature a fountain of Amortentia, the most powerful love potion in the wizarding world. Is this where love potions were first created? And how? What secret ingredient have the Unspeakables discovered?

Could they have solved the mystery behind Foreigner’s 1984 power ballad hit I Want to Know What Love Is? And what of the power of love: the magic that managed to save Harry Potter from the killing curse? Think of the secrets behind those locked doors!

What lies beyond the veil?

Last, but certainly not least, is the Death Chamber. Death, of course, is one of our great Muggle mysteries: the great unknown. Yet wizards seem to know something we don’t. Just look at ghosts, at the Resurrection Stone, at Harry Potter’s strange purgatory dream in Harry Potter and the Deathly Hallows. But most of all, look at the ancient stone archway that stands in the middle of the Death Chamber, with its veil, through which Sirius Black famously fell, never to return. It’s a portal from which the whispers of the dead can be heard.

What is the veil? It’s one of the Harry Potter series’ great questions. Could it be a gateway between the living and the dead? The entrance to the afterlife? And what happened to Black once he passed through it? Did he die, or just make a one-way journey? If it is a gateway, why can’t people come out the other side?

If we knew, of course, then there would be little point in calling it the Department of Mysteries.