Art Mumby is just a normal boy living in space, but all that changes when an ancient race of gigantic white spiders called the First Ones arrive to seize his family home, Larklight. Forced to flee, Art and his annoying sister Myrtle are chased across the galaxy, from the fiery rivers of Mars to the distant rings of Saturn. But the First Ones have trouble on their hands.

They don't bank on Art falling in with Jack Havock and a motley crew of notorious space pirates.