After a catastrophic meteorite impact that kills millions of people, a space tracking system named Spaceguard is developed to provide an early warning if any more objects are headed our way.
In the year 2131 Spaceguard detects a large object entering our solar system. An unmanned probe reveals that the object is not an asteroid, but a massive cylinder devoid of any features. The scientists name the object Rama after the Hindu God.
The survey ship Endeavour is hastily dispatched to rendezvous with the cylinder before it leaves our solar system.
The crew of the Endeavour discover that the cylinder is hollow and contains scientific marvels on a massive scale. but as news of their discoveries is sent back to the rest of humanity, fear begins to rise about the intentions of this mysterious object.