Lord Voldemort's Life Consists of What?

AU. Even if Voldemort is keeping his presence secret from the British Ministry, it's known to Dark-aligned groups on the Continent. Voldemort receives a letter from a powerful vampire lord offering a political and personal alliance, by having Voldemort's "heir and Horcrux" betrothed to the vampire lord's grandson. Voldemort has no idea what he's talking about, but he will find out.