Rhan Ico was a female Cardassian and member of the Obsidian Order.

In 2318, Ico was dispatched aboard the Kornaire, posing as a member of the Ministry of Science, to serve as the eyes and ears of the Order on Bajor. Gul Kell believed there was an agent of the Obsidian Order aboard his ship, but believed it to be Kotan Pa'Dar, but the way Ico acted soon changed his mind.

In 2323, Ico was still on Bajor. She helped Kell and Skrain Dukat plot the annexation of Bajor to Cardassia. When Dukat carried out the attack, Ico provided him with firing coordinates and used the cover to steal the Orb of Truth.

In 2328, Ico was able to cause the annexation of Bajor and the beginning of the Occupation. For ten years she had sown the seeds of dissent and chaos on the planet and decided to activate her various schemes, causing Bajor to descend into anarchy. This anarchy gave the Cardassians an excuse to mobilize soldiers as "peacekeepers" and take control of the planet. (TLE - Terok Nor novel: Day of the Vipers)