Inrai

In Poul Anderson's The Fleet Of Stars, the Inrai are Lunarian freedom fighters/terrorists hiding in the Martian desert, attacking caravans. Anachronistic maybe but Anderson makes them plausible. Their cause is hopeless especially when one of their attacks has been repulsed with fatalities. However, they persevere and play a crucial role.

Fenn contacts the Inrai who contact the Lunarians on Proserpina who contact download Guthrie who is now exploring the inner Solar System. Fenn and Guthrie rendezvous in space where, combining their knowledge, skills and resources, they steal data from a gravitational lens and expose an attempted deception of the human race.

From that point on, the reader is concerned about the fate of Fenn, shot dead but possibly to be downloaded and resurrected, and about the consequences of the exposure of the attempted deception. It would be easy to forget the Inrai but they were inserted into the novel for a reason and, without them, Fenn would not have met the legendary Guthrie. The Inrai have in fact furthered the cause of Lunarian freedom.