TimeBomb - The TimeBomb Trilogy 1

New York City, 2141: Jana Patel throws herself off a skyscraper, but never hits the ground. Cornwall, 1640: gentle young Dora Predennick, newly come to Sweetclover Hall to work, discovers a badly-burnt woman at the bottom of a flight of stairs. When she reaches out to comfort the dying woman, she's flung through time. On a rainy night in present-day Cornwall: seventeen-year-old Kaz Cecka sneaks into the long-abandoned Sweetclover Hall, in search of a dry place to sleep.
Instead he finds a frightened housemaid who believes Charles I is king and an angry girl who claims to come from the future. Thrust into the centre of a war that spans millennia, Dora, Kaz and Jana must learn to harness powers they barely understand to escape not only villainous Lord Sweetclover but the forces of a fanatical army .