"When we talked about the Lake at the beginning of the year, I thought it was a theoretical exercise." Hermione whispered.
Cedric and Neville nodded, chewing their gillyweed and wading into the lake.
"No such luck, Miss Granger." Lily replied sternly, handing them mirrors.
"These mirrors are standard issue for aurors. They allow instant communication between one another. We need these not only for underwater communication, but also because we will be working in teams and later separating. Cedric and I will be going down first to clear a path for the two of you. When we get down, we are looking for a diadem; a small silver crown. DO NOT summon it, DO NOT touch it, just help me search and tell me when you find it." Lily made a fist. "If I give this sign in the mirror, we swim up as fast as possible. The gillyweed should be kicking in now. Let's swim."
Gasping for air like she was, Hermione could barely count how many unanswered questions she had.
Why were they seeking this crown?
Why couldn't they touch it?
What were they going to do with it when they found it?
Why were they going tonight?
Why the three of them?
Was this safe?
Wouldn't their housemates notice their absence?
By the time she had tabulated these thoughts they had reached the lakebottom, following a minute after Lily and Cedric. They scoured the ground, uninterrupted and silent, though the occasional pair of red eyes peered at them from above. Hermione barely had time to worry, Lily set their pace so fast, indicating directions for each of them in a patter Hermione eventually deduced to be outward quarter-circles. Efficient for covering a lot of ground.
The haste, the silence, all of it bothered her. And all of it was wasted! Why didn't they just...
"Accio Crown!" she burbled, though it came out "Boggigob Browm."
She saw a glint of silver rushing toward her from not much further out of her quadrant, getting closer. All the while, it was so obvious. Her superiority, their stupidity. Smarter than a Hogwarts professor, they were hardly worthy to hold this beautiful crown, she thought, and she began to place it on her head, raising the mirror to admonish her comrades...
Hermione woke in the hospital wing. Slowly she turned, a headache tossing every thought from her brain, and coughed up a lungful of salty water. She became aware of a loud conversation stopping, and of Madame Pomfrey rushing to her side, then she fell asleep again.
The next time she awoke, she found a pumpkin tart and a chocolate frog sitting on her bedside. Devouring them immediately, she saw a note beneath them.
"I owe you some answers. We'll meet in my office.
-Albus Dumbledore."