Arkold, once a Rephidimite noble, has gone to being a member of the Offworld Legion, an armed force full of outcasts and criminals serving the Kampfzengruppe and the Khattan Emir in undesirable, high-risk duties on the Gateway Worlds. Arkold's latest assignment takes him to the water world of Ashtoreth, where he is put on a living "submarine" called an urgan, commanded by a young noble with no experience. They encounter a creature known as a "Siren", and the untested captain is unwilling to deal with the threat posed by the beautiful but dangerous creature. Arkold acts without orders, firing a harpoon gun at the creature … and, near as can be told, saving the crew.