Mirok was a Romulan scientist who was working on a new cloaking device that cloaked by dematerializing. In 2368, Ensign Ro Laren and Lieutenant Commander Geordi La Forge of the USS Enterprise-D were accidentally cloaked by this device during a rescue mission aboard a Romulan ship that had become disabled while testing the cloak. Mirok was the science officer of the ship and had taken command after the captain had been killed in an explosion. Mirok was the first of several Star Trek roles played by Thomas Kopache.