The Cruciatus Curse, also known as the Torture Curse, is a spell from the Dark Arts in the Harry Potter universe. It is one of the three Unforgivable Curses, along with the Killing Curse and the Imperius Curse. The Cruciatus Curse inflicts excruciating pain throughout the victims body through the use of the "Crucio" incantation and is often used as a method of torture and interrogation. The spell requires the caster to really desire the pain that it inflicts, and as a result, it is not an easy spell to perform for most witches and wizards. The use of the Cruciatus Curse can be devastating, and repeated use of the spell is torture. Bellatrix Lestrange subjected the Longbottoms to such extremes of pain that it sent them insane. Harry tried to use this spell himself twice, but the first attempt was unsuccessful because he did not have the pure evil intent required to cast it. The second time, he successfully used the spell on Amycus Carrow during the Battle of Hogwarts.