Newly promoted to Lieutenant Commander, John Grimes find himself assisting sky marshall Una Freeman in the attempted recovery of Delta Geminorum. Things go haywire, however, when they find temselves lost in the colossal alien spacecraft. Complicating matters is there discovery that the universe they thought they were in is not their own but an alternate and that they've been captured by the omnipotent force of that entire other cosmos. Grimes and the comely policewoman soon find out theat they have been selected as the only inhabitants of a Garden of Eden. But there were two serpents in this one—both of them bicycles!'