In 1900 PD, Sirius was under the command of Captain Johan Coglin and operated under the auspice of the People's Merchant Service. Secretly, the Sirius was under the command of the People's Navy, sent to Medusa as a part of Operation Odysseus for three months. The ship's passage was granted by HMS Warlock after Sirius claimed to need new Warshawski tuners and stayed in orbit.
Sirius was secretly being investigated by the crew of the HMS Fearless, who had suspected the ship being more than it appeared to be. The Havenite consul ordered the Q-ship to break orbit and leave for its part in Operation Odysseus. That brought the immediate notice of Fearless; Sirius attempted to ride a Tellerman wave to get to a Havenite fleet, but Fearless caught up with her. The First Battle of Basilisk took place, leading to Sirius' destruction with all hands. (HH1)