The sixth season of Without a Trace began airing in United States on September 27, 2007. Twelve episodes had been completed before the WGA Strike. A further six episodes were produced after the end of the strike, making this the shortest season of Without a Trace at 18 episodes. 　　This season included a cross-over with CSI: Crime Scene Investigation involving Jack and Gil Grissom tracking a serial killer from Las Vegas to New York. This established Without a Trace as part of the same fictional universe as the trilogy of CSI shows and Cold Case. 　　The sixth season of Without a Trace has not been released on dvd in region 1 but was release in region 2 in Germany on November 20, 2009 on and in the UK on July 5, 2010. 　　Season 6: Episode 01: Lost Boy 　　Season 6: Episode 02: Clean Up 　　Season 6: Episode 03: Res Ipsa 　　Season 6: Episode 04: Baggage 　　Season 6: Episode 05: Run 　　... 　　...