Khalida devours The Way Things Work- the author uses mammoths for all the examples, it's a little tricky at first to sort out what's a joke and what's serious- adds parking meter and hydroelectric dam and space probe and sewing machine and combine harvester and aqualung and a dozen more to her list of words to go back to the encyclopedia with- starts digging into the biology textbook, and fully does not notice the time passing until the loudspeaker crackles on with "It is four fory-five, the library will be closing in fifteen minutes."

...maybe she can just read a little while longer...

That librarian from earlier finds her a few minutes later when she comes into the reading room to shut off the lights!

"-You're still here?"