House of Anubis/WMG

The treasure is an Ankh or a Scarab

The show has an Egyptian mythology theme going on here and the portrait from the attic had Egyptian heiroglyphs written on it. Sarah implied that the treasure will allow the one who holds it to live forever and "tip the scales of life." The Ankh is the Egyptian symbol for life and the Scarab is the Egyptian symbol for immortality.

Close to the former, but not quite since the treasure is called the Cup of Ankh.

Joy is in the Basement

It's implied that she's still in the school, and we've seen the attic already. Now where else is out of bounds that the heroes haven't searched?

Judging from recent episodes, Joy's being kept at her home by her father, who is in on Victor's plan.

The treasure is a Philosopher's Stone

Victor drank some sort of potion in one episode and gave a toast "to life", but commented that "there isn't much left." Add in the fact that he would have to be really old to have his voice on a recording of the Young Sarah, sounding exactly the way he does today, and the implication is that the potion grants him extended life, much like the elixir the Philosopher's Stone produces according to legend. Furthermore, in one recipe for the supposed creation of the stone, one of the steps is symbolized by a raven (Corbierre) and by the burial of a dead body in the earth("Joy is buried"). Since Victor is running out of his own Elixir, it makes sense that he'd want to find the stone and be able to produce as much as he wants. There's only a couple of holes in this theory: How did he produce the original elixir and why can't he make more? Any thoughts?

This would dovetail nicely with all the Harry Potter Shout Outs.
Victor's father created the elixir, but the recipe died with him. Victor's had to cobble a working yet imperfect potion and wants the Cup of Ankh to ensure true immortality.

Victor is bound to the House by some sort of magical phlebotinum.

Thus explaining why, if he hates being around teenagers so much he didn't just get a normal job where you clock out and leave it behind years ago.

Alternatively, the house itself is some sort of phelbotinum. Staying there is what makes him immortal. He's doing experiments and trying to find the treasure so that he can gain an independent source of immortality and leave freely. He hates being around teenagers, but it's preferable to being dead.
It also explains why Victor's still around since he never does any actual work. Trudy runs the place, were it not for the whole conspiracy thing they could downsize him and the house wouldn't skip a beat.

The photo and the toxicology report in Victor's office are fake.

At least one member of Victor's organization works at the hospital where Alfie was staying, and probably more, since he was able to keep Rufus confined to that hospital for a while, meaning he could have arranged to have Alfie's toxicology report changed. And we know from the school photo incident that he knows someone who can alter photographs and as is pointed out on the main page, if he really is the child from the photo and the immortaility elixir doesn't exist, then he should be over 80 years old. Why did he do it? Simple: He knew that people had been going through his office, so he left false information for their benefit.

House of Anubis is the British Blake Holsey High

Nina is Josie, Fabian is Lucas, Amber is Corrine, and Jason Winkler (in the beginning)/ Rufus (after Winkler joins the Dark Side) is Professor Zachary. And what else? OH. Victor is VICTOR Pearson. Everything science is replaced with magic.

Alternatively, they could also both happen to be in the same universe.

Rufus is alive

Rufus somehow figured out he's not immortal and faked his death so that he could take another shot at getting the cup. He's the one the new house mother is working for. It makes sense: everyone knows who he is, so it'd be hard for him to get into the house on his own, therefore he got someone to slip inside for him.
- Recently confirmed, Rufus Zeno is the 'Collector' figure Vera is working for, and is alive. The only reason anyone found this out is because Jerome tagged along at the right time. Quite the shock for him.

The house has a will of it's own

Think about everything that has happened over the past two seasons: Nina arrived at the house and was almost immediately acknowledged as The Chosen One. (By the House opening it's doors to her.) The house later gives her clues to help her find the Cup of Ankh. Then, consider the people she meets while there. Fabian Rutter, the smart and helpful one, more than capable of solving the riddles Frobisher-Smythe created. Amber Millington, who, while being a Dumb Blonde, proves to be a loyal ally and even has a couple of good ideas on how to proceed with the treasure hunt. (More than once, her random comments lead to solutions.) Patricia Williamson, initially a foil to Nina and her enemy, but post-Heel Face Turn, one of Nina's most invaluable teammates, despite her status as The Lancer. Recall that it was Patricia who got Nina to go into the attic at the beginning of Season One, leading her to the first clue and kicking off the treasure hunt. Jerome and Alfie initially start as Those Two Guys, but they later become important allies in their own right. (Admittedly Jerome moreso than Alfie -- without his involvement, they might never have discovered the existence of the Mask's "third eye" in Season 2 -- but Alfie still has his moments.) Finally, at the beginning of Season 2, Eddie Miller arrives at the house early on and turns out to be the one destined to protect The Chosen One. If he hadn't been there, Senkhara would have dragged Nina to the Egyptian afterlife. Summing up, The Chosen One not only arrived at Anubis House exactly when she needed to be there in order to complete the Cup, but she met the perfect set of True Companions as well. My WMG here is that it wasn't a conincidence that all of these people happened to end up at Anubis House. Somehow, the house acted on it's own, reaching out and bringing each of them there.

Patricia and Joy weren't that good of friends.

Isn't it weird how in the beginning(Season 1)Patricia was so worried and concerned about Joy. But, in Season 2 they hang out a bit in the beginning of season 2 but Patricia slowly stops hanging out with her. I mean if she was that devoted to Joy she would've still hung out with Joy even if she was wrong. Right?