Rosko Krystoffe and Derek Schoemakker are on an ambitious quest to Jupiter's moon Callisto with a small crew, which includes Gretchen Tousard and Vanda Shariffe. Their mission is to rescue Eva who is presumed sold into slavery, and to repossess an alien artifact named the Madonna's Cross that is unlawfully held in possession by the Calliston Gabra Shi. As competition increases among the top scientists in OOS and also between the Spirullian Force and SEV's Syncronised Network, Rosko devises a plan to liberate the enslaved people with the aide of his Paragonian Secret Army.