The Terran contingent was delivered by the "Zeus", a warship in the rather piecemeal Solar Alliance Defense Network. The diplomatic mission is merely a cover story for the military objective, which is headed by Colonel Dr. Syree Johnson (ret.), a soldier and military physicist. The true objective involves "Orbital Object #7", one of World's seven moons (known as "Tas" by the locals). It is in very low orbit, is clearly artificial, and was created by the same unknown progenitor race that created the space tunnels. Johnson's mission is to analyze Orbital Object #7, decipher its use, and discover if it can be used as a weapon. Whether it can or not, it is about nine times too large to fit through the tunnel, and Johnson and her team can think of no way to safely disassemble it.