The Kristang kidnapped several hundred humans (mostly children) to Rikers to use for bioweapons testing and implementation. The humans were on two islands, far from the population centers of the planet. The entire world only has a population of less than one million. About five hundred of them were brought to the planet, there were one hundred and eighty two humans still alive on Rahkarsh Diweln when the Merry Band of Pirates went to rescue them.
The Pirates were in the Rahkarsh Diweln star system when Skippy the Magnificent disappeared and both Valkyrie and the Flying Dutchman were dead in space. Joseph Bishop, aboard a defenseless Dragon dropship, was captured by the Thuranin, held on the ship for three days and then taken back to Rikers. The Thuranin experimented on and interrogated him in a Kristang hospital. When Skippy returned, he helped Joe escape the hospital and destroys the Thuranin ship in orbit. The Commandos rescued Joe while the STAR team attempted to capture two Thuranin. Before Valkyrie was repaired, a Thuranin frigate attacked it, believing it was the Bosphuraq Ghost Ship.
The Pirates, aboard Valkyrie, returned to Rikers to send a message to the Kristang (especially, the Fire Dragon clan), Thuranin and Maxolhx that any abuse of humans, past, present or future, would not be tolerated. The Pirates destroyed all military and experimental assets on the surface, sparing all civilian areas. After the planet-wide destruction, they also instructed one of the Fire Dragon clan leaders that they were leaving stealthed satellites in orbit to keep an eye on things and that they must leave the two islands that they held the kidnapped humans on alone because their were graves were not to be desecrated.
The planet was controlled by the White Wind clan of the Kristang until they were destroyed and their assets absorbed by the Fire Dragon clan, at which point control of the planet was transferred to them, leading to tension between the Fire Dragon administrator and the White Wind guards.
The biosphere of Rikers is somewhat compatible with human life. The planet appears to have an Earth-like climate, with tropical areas by the equator and colder areas approaching the poles. It also has regular rain and cold, etc.