Wizard in the Basement, Witch with the Key (гет)

The war is over, and Hermione claims her potions master as a spoil of war - and to save him from Azkaban. He's still a prisoner awaiting trial, though, even if he is bound in the house Hermione, Ron, and Harry share instead of the wizard prison. The Ministry confiscates his wand and fits him with an anti-magic collar, leaving Hermione to hold the end of his (only somewhat metaphorical) chain.
She intended to put him to work discovering a cure for all the witches and wizards Voldemort had ordered turned into werewolves, but Hermione eventually discovers that Severus Snape is a man of many talents. And Severus discovers that being collared isn't so bad after all.