Cambridge Panics as Reporters Uncover Skull Heist

As they always say: It’s not the crime, it’s the coverup (by administrators at the University Cambridge, who are desperately trying to hide from the public the sudden disappearance of a “very expensive” skull from the school library.)
The whole thing started off innocuously enough—someone stole the skull from the library and the library sent out an email asking for it back.
Dear all
Unfortunately a skull has gone missing from the Library’s collection. If someone has borrowed it from the Library without issuing it on their borrowing account ( the skull will have a barcode on it) please could you either return it or get in touch with me straight away so that I can issue it properly on the borrowing account of whoever has it.
The letter reaches a chilling conclusion: “We hope not to have to replace this as it would be very expensive indeed to do so.”
Then the coverup began, according to the Cambridge News:
When the News asked about the missing skull a second email was sent to the student, asking them to delete their original post, which has now been removed.
It read: “It has been brought to my attention that you have decided to share on social media an internal e-mail I sent earlier intended only for members of college.
“This has, as a result, attracted some unwarranted press attention. Please can you remove the Twitter post immediately.”
What are they hiding? How deep does this thing go—six feet???