He was assigned command of the Heran Modality ship Temenus with a secret mission to spread the Unity virus to Human worlds through the shipyards at Aldebran. His cover story was that he was going to trade Romulan command codes to a Ferengi trader known as Khorstai.
Unfortunately for Blaisdell, his ship was sabotaged by Heran rebels who opposed the views of Project Unity. His ship was disabled in space but was rescued by the USS Enterprise. Fearing that his mission might end in failure, Blaisdell secretly unleashed the virus on the crew of the Starfleet vessel. He faced some difficulty in the form of Lieutenant Worf who was close to discovering his origins and planned for one of his colleagues, Vlad Dunbar, to terminate the Klingon but this was thwarted by the scientist Astrid Kemal. His plans on infecting the Enterprise crew were also discovered by the Federation crew due to interference from Dr Kemal.
Blaisdell was arrested and transferred to the USS Marconi which would transfer him to a nearby starbase. There he remained until a surprise Heran attack damaged the base which gave him the opportunity to escape. He killed two security officers and left in a runabout. However, when the Marconi demanded him to stand down, Blaisdell resisted and increased his shuttles warp capability to warp nine. In retaliation, the Marconi fired and destroyed the shuttle, along with Blaisdell. (TNG novel: Infiltrator)