A foolish experiment leads Tilly on a rocky trip through time, and the house seems determined not to let her get back to Ashford. Now she's not only stuck in a series of wrong times, so is Ashford's assistant Thomas, who was sent through to look for her. Her guilt over reopening the portal and sadness from losing Ashford threaten to overwhelm her as she struggles to keep going, all the while terrified she'll never see any of her loved ones again.
Try as he might to find where and when Tilly ended up, Ashford can't make any headway with the portal. He turns to his family's ancient grimoire to help him locate her, despite the fact that it could have life-threatening consequences.
Meanwhile, a pregnant Serena is finding out for herself just how dangerous the old book is, keeping her late night reading a secret from her husband Kostya, who's been keeping his own secrets from her.