Scarlet Snakes with Golden Fangs

Ninety years after Harry Potter defeated Voldemort, Slytherins and the old pureblood families have been forced into hiding by the prevalent and persistent anti-Voldemort movement. Being too much a wizard, too old-fashioned, or simply too proper can lead to social suicide. And why are hundreds of witches and wizards across England suddenly able to speak with snakes? (T for language)