I enjoyed this as a child but did't realize it was geared towards elementary age kids. Though the quantum physics aspects of time and space travel, seem out of place in a child's book. A great evil is stalking the universe and Meg, Charles and Calvin must fight it to rescue their father. It's a great coming of age story with religious undertones. I enjoyed the quest and the interaction between the three children, the three wise "women" and the strange creatures. A very good start to the Time Series.