“When one wizard saves another wizard’s life, it creates a certain bond between them. And I’m much mistaken if Voldemort wants his servant in the debt of Harry Potter.”

“I don’t want a connection with Pettigrew!” said Harry. “He betrayed my parents!”

“This is magic at its deepest, its most impenetrable, Harry. But trust me, the time may come when you will be very glad you saved Pettigrew’s life.” - Harry Potter and the Prisoner of Azkaban