Memento Mori Series by C.N. Crawford

Seventeen-year-old sorcerer Tobias Corvin tumbles through a blizzard and arrives—half frozen and half dead—in another world. Trapped in Boston, he tries to blend in at an old boarding school while secretly plotting to save his home. But if anything can distract him from his mission, it's the wild-haired and intriguing Fiona. She is determined to learn the truth about his dangerous magic. When a spectral army from Toby's world begins slaughtering Bostonians, he and Fiona must stop the carnage... moreSeventeen-year-old sorcerer Tobias Corvin tumbles through a blizzard and arrives—half frozen and half dead—in another world. Trapped in Boston, he tries to blend in at an old boarding school while secretly plotting to save his home. But if anything can distract him from his mission, it's the wild-haired and intriguing Fiona. She is determined to learn the truth about his dangerous magic. When a spectral army from Toby's world begins slaughtering Bostonians, he and Fiona must stop the carnage. They face unspeakable dangers unearthing the dark secrets of New England's past—a past that holds the key to saving both worlds from destruction. less