The Oblivion Hex by RA Westwood

Rated: 3rd-5th Years •
Summary: Auror-turned-Librarian, Noah Sizemore, traded dark wizards for dusty books when the Dark Lord fell. Incognito among American Muggles, his ho-hum life is turned upside-down when an old friend appears with a scrap of parchment telling of a hex which can undo history. Together the two rekindle their Auror ways on a globe-hopping adventure to find this darkest of hexes before it falls into evil hands...