Does an ancient marker found in the Bahamas hold the key to the survival of humankind? The last thing Dr. Tegan Strong ever imagined was having to run for her life. As a gifted virologist, she thought she'd be enjoying recognition for her incredible medical breakthrough. Instead, the leader of a clandestine government agency wants her dead and she has to disappear. Tegan assumes a new identity and finds sanctuary aboard a charter sailing yacht. Just when it looks like she's escaped her past and can enjoy life again, she makes an amazing discovery off of Great Guana Cay. Thirty feet below the surface and covered with strange symbols lies a marker of unknown origin. The artifact isn't kept secret for long. Before Tegan and her friends can unravel the mystery, she is once again forced to hide. This time it's not only the covert agency hunting her. The President of the United States also wants control of the marker, and his interest in it is far more sinister than anyone would ever believe. Time is running out. Tegan and her friends must decipher the meaning of the symbols before it's too late. The fate of humanity is at stake.