10 of the cleverest clues JK Rowling hid in the Harry Potter books

Little did we know that just two books later we'd discover he was one of the most important characters in the boy wizard's life.

And when Harry got to Grimmauld Place, feeling as though he'd entered the home of a "dying man", we should have twigged it was Rowling laying the foundations for her heartbreaking Order of The Phoenix plot.

We can't forget that the bike that brought Harry to the Dursleys was the vehicle that eventually took him away either.

Now here's one you might have missed if you only watched the films. Back in Chamber of Secrets, Nearly Headless Nick concocted a plan to get Harry out of trouble by convincing Peeves to break a vanishing cabinet.

A few years later, in Order of The Phoenix, Fred and George shoved a Slytherin lad by the name of Montague into an odd cabinet headfirst. Montague apparated to escape and ended up in the u-bend of a Hogwarts toilet, but that didn't stop him revealing the cabinet's potential to one Draco Malfoy.

And we all know what Draco did with it now, don't we?

What you might not have copped, however, was the debut of the cabinet's Borgin and Burkes twin. When Harry mispronounced Diagon Alley while travelling by Floo Powder in Chamber of Secrets and found himself in the sinister shop, he hid in a strangely large cabinet to avoid Draco Malfoy.

He never closed the door fully, though, so it couldn't possibly have sent him to Hogwarts.

Remember that cursed opal necklace that almost killed Katie Bell in Half Blood Prince?

Did you clock that it was mentioned in Chamber of Secrets too?

When Harry arrived at Borgin and Burkes he noticed Draco eyeing up a necklace, and when he got a closer look he discovered something rather chilling written on the label...

Do not Touch! Cursed. Has claimed the lives of nineteen Muggle owners to date.

It's no wonder Draco knew where to go to find some killer jewellery.

Speaking of jewellery, quite possibly the most famous and beloved plot point Rowling ever dropped first pops up in Order of The Phoenix.

While cleaning the house Harry, Ron and Hermione come across a heavy old locket that nobody can open and decide to cast it aside because they can't be bothered to deal with.

Cue a billion Potterhead jaws dropping when R.A.B made his revelation at the end of Half Blood Prince. We all knew it had to be the missing horcrux.

Bravo, Ms Rowling. Bravo.

If you were reading Chamber of Secrets quite closely you might have noticed that Ginny held the whole family up on the way to the Hogwarts Express because she'd forgotten to take her diary.

Imagine how easily Lord Voldemort's plans to open the chamber and unleash the beast within would have been scuppered if she'd failed to take that little notebook to school?

They may have hated Divination but Harry and Ron sure showed a talent for predicting the future – even if it was accidental.

When struggling to come up with predictions for their Divination homework the pair decided to simply make some up – and they pretty much mirror the events of the Triwizard tasks.

First up, Harry's "in danger of burns", which we can of course attribute to the Hungarian Horntail and the dragons. Then it's time to "lose a treasured possession", aka Ron, whom the Merpeople take beneath the lake. That covers the whole drowning element.

And finally Harry's “stabbed in the back” by Mad Eye Moody/Barty Crouch Jr. and most definitely comes off “worse in a fight” with Voldemort, returning traumatised by the Dark Lord's rise and the death of Cedric Diggory.

Pity the pair never considered a career in teaching Divination, really.

Remember reading about that room full of toilets, which Dumbledore just so happened to discover back in Harry Potter and The Goblet of Fire?

“Only this morning, for instance, I took a wrong turning on the way to the bathroom and found myself in a beautifully proportioned room I have never seen before, containing a really rather magnificent collection of chamber pots", Harry overheard him saying. "When I went back to investigate more closely, I discovered that the room had vanished.”

Memories of the Hogwarts headmaster's toilet habits came, err, flushing back when Harry discovered the Room of Requirement just in time to start work with Dumbledore's Army.

The first time we hear about Aberforth Dumbledore is when his brother, Albus, mentions him in passing to Harry. He doesn't say much about him, other than that he got in a spot of bother for practicing inappropriate magic with goats.

In Order of The Phoenix, when the DA needs somewhere safe to meet, the trio opt to set up shop in the Hog's Head and note that it smells of goat. But, most importantly, Harry notices something about its landlord.

"He was a grumpy-looking old man with a great deal of long gray hair and beard. He was tall and thin and looked vaguely familiar to Harry."

Of course, we later discover that he is in fact Aberforth Dumbledore. And the magical circle of life is complete.

Now here's one that's a little bit more intricate and – if it really was a plot device – incredibly clever.

In Harry Potter and The Half Blood Prince, the Boy Who Lived helps good pal Ron survive a poisoning by running to nab a bezoar from Professor Slughorn's stock.

He knows it'll do the trick because his very cleverly annotated potions book told him so.

And in his very first potions class, all the way back in Philosopher's Stone, what does Half Blood Prince Severus Snape ask him?

"Let's try again, Potter, where would you look if I told you to find me a bezoar?"

Minds all over the Muggle world blown.

We've already established that the vanishing cabinet has roots throughout the book series but remember when Harry decided to hide his rather dangerous old potions book – the one Snape annotated – in it?

And he came across a rather odd looking tiara?

Cue another massive Deathly Hallows jaw drop when every single fan who'd read the novels just KNEW it had to be Helena Ravenclaw's diadem and one of the last remaining horcruxes keeping Voldemort invincible.