Columns: Series | Episodes | Series premiere | Series finale | Region 1 | Region 2 | Region 4
Pilot | 1 | 18 February 2008 | 18 February 2008 | N/A | N/A | N/A | 1 | 6 | 25 January 2009 | 1 March 2009 | 20 July 2010 | 20 April 2009 | 6 August 2009 | 2 | 8 | 10 January 2010 | 28 February 2010 | 21 September 2010 | 12 April 2010 | 5 August 2010 | 3 | 8 | 23 January 2011 | 13 March 2011 | 3 May 2011 | 28 March 2011 | 5 May 2011 | 4 | 8 | 5 February 2012 | 25 March 2012 | 15 January 2013 | 23 April 2012 | 7 June 2012