She tried to convince Jarvis Bennett to not destroy the Silver Carrier. When the Second Doctor and Jamie McCrimmon arrived on the station, she examined them and reported to Bennett that Jamie was lying about their presence on the Silver Carrier. She later introduced Zoe Heriot to the Doctor and Jamie.
Corwyn believed the Doctor's claims that the Cybermen could get aboard the station and tried to convince Bennett to take precautions, with no success. She confided in the Doctor her fear that Bennett couldn't face the truth.