In 2200 a second cylindrical intruder arrived in the solar system. The citizens of Earth dusted off the old procedures that had been developed after the first Rama had departed, and prepared to rendezvous with Rama II. A crew of twelve was chosen for the mission. Soon after the rendezvous, the dozen reported that the second Rama spacecraft was nearly identical to its predecessor. The humans encountered new mysteries and wonders, including some alien beings, but were still unable to answer questions about the origin and purpose of Rama.

Three strange deaths among the crew created great concern back on the Earth, where all aspects of the historic mission were followed on television. When the giant cylinder underwent a midcourse maneuver that placed it on a trajectory that would impact the Earth, this concern changed to alarm and fear. The leaders of the world reluctantly concluded that, in the absence of any other information, they had no choice except to assume that Rama II was hostile. They could not allow the alien spacecraft to impact the Earth, or to come close enough that it might deploy any advanced weapons it might possess. A decision was made to destroy Rama II while it was still a safe distance away.

The exploration crew was ordered home, but three of its members, two men and a woman, were still on board Rama II when the alien spaceship avoided a nuclear phalanx launched from the Earth. Rama maneuvered away from the hostile Earth and departed at high speed from the solar system, carrying both its intact secrets and the three human passengers.

It took thirteen years at relativistic velocities for Rama II to travel from the neighborhood of Earth to its destination, a huge engineering complex called the Node that was located in a distant orbit around the star Sirius. The three humans on board the giant cylinder added five children and grew into a family. As they investigated the marvels of their home in space, the family again encountered the extraterrestrial species they had met earlier. However, by the time they reached the Node, the humans had already convinced themselves that these other aliens were, like them, only passengers in Rama.