Star is correct. The university will hold 'balances due' (including library book fees) over your head until you pay. You won't be able to get transcripts, grades, etc.
But don't let that scare you! Like I said in the
other thread that was mentioned here, just take a deep breath - everything can easily be sorted out.
First: ask a librarian for help. This could be a mis-understanding or error and you may not have to pay that large fee if you talk with them.
See the borrowing/fees policy here:
http://library.mcmaster.ca/borrow#Re...iods_and_Fines
Under "Penalties for Not Returning Materials" it reads:
"If you don't return an overdue item we suspend your borrowing privileges,
charge the cost of replacing the book, and a $25 non-refundable administrative fee per item."
So at most you'll be charged $25 per book, since you returned them.
My guess is that they may have just been delayed getting checked back in because of the weekend. Its not like you held onto the books for years and forgot to return them for a long period of time. If you were a day late returning, or confused about the due date I'm sure you can get it sorted out with one of the librarians. They are really nice people, you just have to talk to them