Procyon II is a Sapphire World notable for being the homeworld of the Chenjesu and the hybrid race, the Chmmr. It is generally accepted that the Chenjesu evolved on this planet, drawing energy from the native mineral resources and the weak electromagnetic radiation that reaches the planet from its sun, Procyon. Following the defeat of the Alliance, the Ur-Quan slave-shielded both the Chenjesu and Mmrnmhrm on this planet. Once imprisoned on the planet, the two races began The Process that eventually produces the new Chmmr race.
Similar to other slave-shielded worlds, the Ur-Quan placed a Starbase in orbit. The Starbase is currently abandoned, its former crew of Chenjesu and Mmrnmhrm somehow transporting to the surface of the planet, though the base continues to be maintained and defended by simple, preprogrammed robots.