Lupin Admits He Hid Sirius's Animagus Status from Dumbledore

Remus Lupin confesses that he had struggled throughout the year with whether or not to tell Albus Dumbledore that Sirius Black was an Animagus. He admits that he was too cowardly to reveal that he had once led others into becoming illegal Animagi and that he betrayed Dumbledore's trust during his time at Hogwarts.