sentence: series overview notes : miniseries ( 2003 ) television series season 1 ( 2004 -- 05 ) season 2 ( 2005 -- 06 ) season 3 ( 2006 -- 07 ) razor ( 2007 ) season 4 ( 2008 -- 09 ) the plan ( 2010 ) webisodes ( 2006 -- 09 ) broadcast ratings online availability in january 2006 , apple began offering the miniseries , season 1 and season 2 episodes for purchase on the u.s. version of its itunes store .