In this sentence, hoc anno is the subject of esse, so I expect it to be in the accusative, "hunc annum". Also, futura should agree in gender to annus, masculine. What am I missing?
(If it's not obvious, this is the blurb for Harrius Potter et Camera Secretorum.)
Harrius Potter est magus. Discipulus est secundarius Scholae Hogvartensis Artium Magicarum et Fascinationis. Vix scit hoc anno tot miracula futura esse quam anno proximo
Harry Potter is a wizard. He is in his second year at Hogwarts School of Witchcraft and Wizardry. Little does he know that this year will be just as eventful as the last . . .