First broadcast in 2004, The 4400 told the tale of 4400 people who had apparently been returned to Earth after having been systematically abducted over the previous fifty-odd years.

Upon their return, the 4440 are put under the remit of NTAC (National Threat Asessment Command) and by the end of Season One it became apparent that not only had a number of them been returned with some remarkable powers, but that they had actually been abducted by people from the future and sent back in order to avert a potential catastrophe.

Later seasons expanded on the sci-fi element with many more of the returnees developing powers and major player Jordan Collier (Billy Campbell) offering ordinary people a chance at developing their own powers — a 50-50 gamble resulting in either death or yet more trouble for NTAC.

Throughout all four seasons, NTAC's leading investigators were Tom Baldwin (Joel Gretsch), whose nephew Shawn Farrell was one of the returnees, and Diana Skouris (Jacqueline McKenzie) whose eventual adoptive daughter Maia had been returned with the ability to see the future.

Despite being one of the most promising sci-fi series of recent years, the axe fell after the conclusion of the fourth season, leaving many plot strands unresolved. However, it was announced during 2008 that the final two of the four planned novels would conclude the storylines left dangling after cancellation.

In the UK The 4400 is largely unknown, another victim of the increased ghettoisation of imported US action/sci-fi dramas, being available exclusively to Sky's pay TV channels and therefore permanently unavailable to any free-to-air audiences.