When the tail of the comet Bhaktul flicks through the Earth’s atmosphere, deadly particles are left in its wake. Suddenly, mankind is confronted with a virus that devastates the adult population. Only those under the age of eighteen seem to be immune. Desperate to save humanity, a renowned scientist proposes a bold plan: to create a ship that will carry a crew of 251 teenagers to a home in a distant solar system. Two years later, the Galahad and its crew—none over the age of sixteen—is launched.

Two years of training have prepared the crew for the challenges of space travel. But soon after departing Earth, they discover that a saboteur is hiding on the Galahad! Faced with escalating acts of vandalism and terrorized by threatening messages, sixteen-year-old Triana Martell and her council soon realize that the stowaway will do anything to ensure that the Galahad never reaches its destination. The teens must find a way to neutralize their enemy. For if their mission fails, it will mean the end of the human race….