Which character in Harry Potter and the Prisoner of Azkaban helped Harry rescue Hermione Granger from a troll?
Harry Potter and the Prisoner of Azkaban:  Along with friends Ronald Weasley and Hermione Granger, Harry investigates Sirius Black, an escaped prisoner from Azkaban who they believe is one of Lord Voldemort's old allies. Hermione Granger:  After Harry and Ron save her from a mountain troll in the girls' toilets, she becomes best friends with them and often uses her quick wit, deft recall, and encyclopaedic knowledge to help them.
Ronald Weasley