Sol 2781 is the third of three full-length novels set immediately after the novelette length short story Hera 2781. Major Drago Tell Dramis is celebrating the fact that the saboteur has been caught, and the Earth solar arrays will be safe now. The arrest of a member of the main board of Hospital Earth has consequences though. As Drago hits orbital levels of fury, and declares his own personal war against Hospital Earth, he's hit by even more unexpected problems. There's a joke that says one birth member of the Tell clan attracts trouble, two birth members of the Tell clan invite minor disasters, while three is the critical mass that triggers cataclysmic events. As the danger mounts, the question is whether Drago and his two cousins, Jaxon and Gemelle, can prove an alternative theory. Are three members of the Tell clan really the critical mass that resolves cataclysmic events? This extra-long novel concludes the Drago Tell Dramis 2781 sequence of Hera 2781, Hestia 2781, Array 2781, and Sol 2781.