Captain of the MCRN Cydonia, the Martian commander who saved the Roci and now generously rearms and escorts it toward Io.
Captain Richard Tseng commands the MCRN Cydonia, one of the Martian fast-attack cruisers that shadowed Nguyen's destroyers and, at Avasarala's plea, intervened to save the Rocinante. Gracious and decisive, he hails Holden after handling his own damage control, credits the Roci's first kill with breaking the UN defensive screen ("they shouldn't have turned their backs on you"), and without a moment's hesitation resupplies the Roci — fourteen torpedoes and point-defense ammunition ferried over by the destroyer *Sally Ride* — as well as the Force Recon equipment Holden requests for Bobbie Draper. Amused and intrigued by the improbable sight of a cashiered UN officer flying a stolen Martian torpedo bomber crewed by Martians and a senior UN politician, he wants to hear the whole story over a drink someday.
He and his surviving ships escort the Roci on its burn to Io.
Not physically described; present as a courteous, quick-thinking Martian naval captain's voice over the comm.
MCRN Cydonia's captain, the Martian ally who rescues, rearms, and escorts the Rocinante toward Io.