Space Station Q4 was a 24th century Earth space station in the fifty-fourth sector of chartered space on the other side of the Mutter's Spiral. It worked in co-operation with other stations like Q3, B5, and P4. Originally, in 2381, the station came under attack from the Garvond and all personnel were aged 300 years as the Garvond began to feed on time. Travelling back in time with the Garvond, the Seventh Doctor, Ace, and Benny Summerfield were able to deflect the attack of time energy back at the Garvond, destroying it. As a result, the crew of Q4 was still alive. (PROSE: The Dimension Riders)
- Q4 continues the human system for naming space stations, which started in the 21st century with Space Station W3. (TV: The Wheel in Space)