An edited version of the pilot miniseries was aired on NBC on January 9, 2005, five days before the Sci-Fi series premiere. NBC also aired three selected first-season episodes to promote the show in advance of the second-season premiere in July 2005. The series ran for four seasons between 2004 and 2009. The second season was split into two halves screened several months apart. Due to production delays caused by the 2007–2008 Writers Guild strike, the fourth season was also split into two parts, with a seven-month hiatus in between.