Torchwood: Miracle Day is the fourth series of Torchwood, which began airing on Starz on July 8, 2011. It's a ten-part miniseries, similar to Children of Earth in tone. The storyline is a BBC America / Starz co-production that's set in both Britain and America. Covering the equivalent screen time of 20 episodes of the original Doctor Who series, this makes it the longest single storyline in the history of the franchise. For an episode guide, see Torchwood's Recap page.