I just finished reading this book, and this was great! The main character, Suzy, is really smart. She loves sharing facts with her best friend, Franny, until everything changes in 6th grade. Franny starts to hang out with the more popular and girly girls, and wishes that Suzy would start acting "normal." So Suzy tries to tell her how she's acting. However, this does not help their friendship.
Later, Suzy finds out that Franny has drowned. She resorts not not talking and blames Franny's death on a jellyfish. Suzy decides to prove that her theory is correct. This book was wonderful, and I recommend this to anyone looking for a book with friendship, loss, and of course jellyfish.