Hermione stays in the hospital wing for a week while the potion wears off. Harry and Ron visit her, and on the way out they find Filch upset about water coming from Moaning Myrtle's bathroom. Myrtle, miserable as always, said someone threw a book at her. Harry picks up the book and finds it is a blank diary that belongs to T.M. Riddle, a name Ron recognizes as someone who won an award for service to the school 50 years ago. Hermione, all healed, suspects the diary is in invisible ink, and suspects that Riddle had something to do with the Chamber of Secrets. Lockhart plans a Valentine's Day celebration to boost morale, and Harry gets an embarrassing singing valentine from Ginny Weasley. In doing so he drops his books and his ink bottle, and Malfoy grabs the Riddle diary. Harry grabs it back, and notices the book is clean of the split ink. Alone, Harry tries writing in the diary, and the diary writes back! Tom Riddle tells him that he stopped the person who had opened the chamber. He brings Harry into his memory of Tom requesting to stay at the school over the summer. He is refused, due to the attacks. Riddle hides in the dungeon and catches a large boy named Rubeus who Harry recognizes, with a creature in a cage. He attacks the creature, saying that the attacks must be stopped. Harry is thrown out of the memory and back into his dorm just as Ron enters. Harry quickly tells Ron that the boy Rubeus from the memory was Hagrid: Hagrid had opened the Chamber 50 years ago!