Gallant by V.E. Schwab

Olivia Prior has grown up in Merilance School for Girls, and all she has of her past is her mother’s journal—which seems to unravel into madness. Then, a letter invites Olivia to come home to Gallant. Yet when Olivia arrives, no one is expecting her. But Olivia is not about to leave the first place that feels like home; it doesn’t matter if her cousin Matthew is hostile, or if she sees half-formed ghouls haunting the hallways.

Olivia knows that Gallant is hiding secrets, and she is determined to uncover them. When she crosses a ruined wall at just the right moment, Olivia finds herself in a place that is Gallant—but not. The manor is crumbling, the ghouls are solid, and a mysterious figure rules over all. Now Olivia sees what has unraveled generations of her family, and where her father may have come from.