Cal has been undercover on Shadow Island investigating the secrets hidden beneath the surface of this would-be tropical paradise. Evading search parties while being spied on by robotic pythons, planning rescue missions, being chased through the forest and sneaking through hidden tunnel systems . . . it's now just an average day for Cal.

Trapped in the leader's office, how can Cal evade capture and continue his double-act with his twin brother, Ryan? As his enemies increase and the dangers multiply at every turn, at least he knows he can count on SI-6-or can he? The clock is ticking. Any second could be his last.