Sci- Fi fans will like the time-travel element of this story and Fantasy fans will love the witches and magic. All teens will be able to relate to the themes of good vs. evil, sibling rivalry, wanting to fit in, and feeling like your parents don't understand. Some subject matter to consider: Tamsin smokes and uses her fake ID to go clubbing at night, there is some implied sexual situations, and a scene where an arm is slashed with a knife. Tamsin also has a gin-loving aunt. Because of its subject matter, this fast-paced fantasy is probably best for the fourteen and up crowd, rather than the publisher's recommended age of twelve.