Enchanted Glass is a fantasy novel by Diana Wynne Jones which was first published in 2010.
Shortly after Andrew takes possession of Melstone House, Aidan Cain appears on his doorstep, asking for help.
His recently deceased grandmother had told him that the owner of Melstone House could help him, if he ever needed it.
Aidan is being pursued by an unknown force, which turns out to be the fairy king Oberon, who thinks he is his son.
Together, Andrew and Aidan must unravel the mystery of Melstone House, and gain control of their magic.
When he was a child, Andrew's grandfather taught him quite a bit of magic, but as he grew up, he forgot much of it.