The Familiar Owl
Madam Pince was working away at her desk when she noticed that an owl had entered the library. It was patiently waiting in front of her desk. She thought for a moment that it had to be Harry Potter's owl. When the owl saw that it had her attention, it barked, "Book, book, book, BOOK!"
Madam Pince looked at the owl and, questioning her own sanity for a moment, complied. She placed three recently-returned books down in front of the owl. As she watched, the owl looked down at the books, which shrank. The post-owl bindings on the owl's leg wrapped around the now-shrunken books on their own before the owl quickly launched itself into the air and flew out the door.
She shook her head and wondered if it was appropriate to have herself examined by Poppy.
The next day, Madam Pince was again disturbed by the same owl, who had the previous day's pile of books on the desk and again barked, "Book, book, book, BOOK!"
Irma Pince shook her head and wondered what the owl was doing with the books. She stood and walked to the returns bin, but Penelope Clearwater, the Head Girl and, ostensibly, her assistant, had re-shelved the books returned from the students earlier in the morning. She saw a few books which Hermione Granger had looked at just that morning and placed them in front of the owl. Again, to her amazement, the books shrank and attached themselves before the owl flew out the doorway.
The next day, the Hogwarts librarian was once again disturbed by the owl, who squawked in a rather irritated fashion, it seemed, "Book, book, book, BOOK!"
By now, Irma's curiosity has gotten the better of her. She had four books she had previously selected and sat them down in front of the owl. She quickly bit into, then swallowed the potion-filled pill she had asked Severus Snape to make for her.
The potion within would allow her to track the owl wherever it went.
She followed the owl when it left the library. She followed it as it flew across the grounds. It flew over the Black Lake which required she walk along the shore.
On the other side of the lake, the owl disappeared into the Forbidden Forest. Although she had spent the better part of the last half-century confined within the walls of the school, Irma followed the owl into the forest.
Just on the other side of the first line of trees was a small marsh fed by the lake. The owl had stopped on the side of the marsh.
Madam Pince, now thoroughly curious, hurried over and saw there was a familiar-looking toad next to the owl, examining each book, one at a time. Irma came close to the two obviously-magical animals just in time to hear the frog saying, "Read it, read it, read it..."