Irim Su is a female Lem Bataan who accompanied His Excellency Ambassador Ohl Ain on his diplomatic visit to Fengrir. She was present with him at a reception hosted by the Proconsul of Fengrir, the Honourable Chellis Bel-Osanda, and served as his attaché.
When that reception was attacked by the rogue counterpart Maber Castigon, Doctor Su and Ambassador Ain were evacuated from the House of Governance and escorted to safety by Ider Firenz. Although others were injured and killed, both Su and Ain were kept safe (→SFTD).
Irim Su is a Doctor of Virology, and conducts research for the Confederation Academy of Sciences on Phnemaph, the Lem Bataan homeworld.
Following Elm Caden's return from the Perseus arm in 3745 ELC, he met with Su aboard the science vessel IRV Vavilov. There Su confessed to be working on behalf of the Soor-Ais, the Lem Bataan security service. She stated that her true purpose in Imperial Combine territory was to study the actions of Voice, which she called 'the Manifold Hand'. Based on what she learned, and the dire events she predicted, was Su who arranged the meeting between Caden and Glanced Esteem (→FSS).