Harry's Failed Summoning Charm Disturbs the Water
Pages 561-563
Harry suggests using a Summoning Charm to retrieve the Horcrux from the center of the lake. Dumbledore allows him to try. However, instead of summoning the Horcrux, Harry's spell disturbs something lurking in the water. A large, pale figure momentarily surfaces and then vanishes. Dumbledore explains that these are Inferi.
