Knights of the Cross: Alien Arrival is an action and adventure, science fiction novel about aliens known as Psystructs who set their sights on planet Earth. When they arrive, they find a large group of high school seniors on a class field trip and decide to murder them and their teachers. Twelve of the students escape this initial attack and are chosen to become the Knights of the Cross, and to them falls the responsibility of defending Earth from this alien menace. Along the way, their parents are drawn into the fray, while their human identities are branded as fugitives by a secret organization, known as A.R.C. At the same time, they are aided by two mysterious collaborators—Manuel and Justice.