Or, a Portrait of the Mathematician as a Young Man (слэш)

Historical AU. University of Cambridge, 1931. Remus J. Lupin, a mathematics scholar at King’s College, has fallen in with a set of friends who called themselves The Marauders—and at its masthead the dissolute aristocratic heir, Lord Sirius Black.
A roman a clef of Alan Turing's life woven with fantasy inspired by Brideshead Revisited, told by Harry Potter characters in period clothing. Illustrated.