What’s there to say: proper, good, classic sci-fi. As with Childhood’s End, it is well deserving of it’s place in the “SF Masterworks” series.
This time, instead of actual aliens coming to Earth and a prophecy of how humanity will eventually evolve, in Rendezvous With Rama we have a large alien vessel entering the solar system on a path that will take it inside the orbit of Mercury, around the Sun, and then, is anyone’s guess. Will it adjust it’s trajectory, pull a breaking manouvre and find a stable orbit in the solar system, or will it use the Sun and sling shot elsewhere? Where did it come from, who sent it, who or what is inside, what is it’s purpose?
Set in a time when humans have colonised several planets and moons in the solar system and space flight is quite normal, we have one space ship — the Endeavour, captained by a big fan of James Cook — that is able to get some fuel and rendezvous with this vessel and investigate it. However, once the vessel has passed inside the orbit of Mercury, the Mercurians decide to take matters into their own hands and ignore what the rest of humanity has to say on the matter.
As i say, this is a proper old school sci-fi first contact story at its best and well deserving of its place as a “SF Masterworks”.