Maggie Evans, a high school biology teacher with her feet on the ground and her future planned, has her world turned upside down by her gifted, troubled student, Craig Vaughn, who draws her into an adventure that takes her from the hot, water-rich Amazon to the frigid, arid surface of Mars. It begins with Craig's interest in a mysterious meteor that appears to contain evidence of extraterrestrial life. Her marriage threatened by her infatuation with Craig, and carrying a child she never wanted, Maggie faces her greatest peril 50 million miles from home as she finds what she came for…proof of non-human intelligence.