For Want Of A Malfoy (Book One)

Everybody knows about the Malfoys. Everybody knows, or is at least suspicious, that the Malfoys supported Voldemort. They, along with the Blacks, are the most well-known pureblood family in the world (unless you want to count the infamous redheaded Weasleys).
What no one ever mentioned in the books though, is the Fletching family. Pureblooded. Voldemort supporters. Notorious for their cruelty, wealth, and self-importance. The Fletchings were always very close to the Malfoys, and when Siger and Eliza Fletching had a baby girl the same age as Draco, the two families became even closer.
Then Voldemort fell. Siger and Eliza were immediately sent to Azkaban. Their daughter, Amelia, was raised by the Malfoys. Draco and Amelia (or Dragon and Lia, as they call each other) grew up as best friends and play mates, two peas in a pod.
But what happens when the two young Purebloods are sent to Hogwarts?

Cover art from google.