Watch Eureka Season 4 Episode 4 online for free. Watch this newest season of the episode of Eureka which is episode 4 entitled as "The Story of O2." The new episode is scheduled to air on July 30, 2010. The following is a summary of what to expect from episode 4: As Eureka celebrates Space Week, Dr. Ramsey unveils his cutting edge invention that could allow colonization of Mars. Unfortunately, a slight malfunction may cause it to incinerate Eureka before the dream is realized. Equally bad is that Eureka's go-to guy for crisis intervention has just gone to Boston to visit his daughter at Harvard.