Now years latter the two families return for the kids to start at Hogwarts under a very changed Headmaster.
When they heard that their children was in the cross hairs of Voldemort James Pettigrew and Lily Prince came together and took their families into hiding leaving Dumbledore to take on the dark lord himself only winning the duel with the help of the Elder wand to blast the man and his Horcruxes to kingdom come.
