In this latest duel, the brothers debate whether or not Albus Dumbledore suspected Sirius Black to be innocent of betraying James, Lily and Harry Potter. Why didn't Dumbledore mention Sirius's apparent betrayal when Hagrid mentioned getting his bike? Could Snape have told Dumbledore that Pettigrew was the traitor? Why didn't Dumbledore visit Sirius in prison? Could Sirius really convince Dumbledore of his innocence without any proof in the space of 20 minutes? The brothers tackle these questions and more.