One of the most critically acclaimed series from Vertigo, Sandman Mystery Theatre follows the exploits of Wesley Dodds, a man who protects the innocent from the Manhattan underworld. Written by Matt Wagner for the majority of its run with art from Guy Davis and others, Sandman Mystery Theatre re-told the early years of the original Sandman during the 1930's before he was a member of the Justice Society of America and dealt with mature themes such as racism and the politics of the approaching Second World War. The series re-worked some elements of previous DC Comics continuity, for instance, Dian Belmont did not die, and Sandy Hawkins did not exist except as a fictional character. However, Wagner did include references and appearances from other JSA members of the time and mainstream DC continuity of the time did incorporate the series to certain degrees. The series was launched due to the popularity of Neil Gaiman's The Sandman (1989).
Outside of the main series, there was one annual (Sandman Mystery Theatre Annual) the special one-shot Sandman Midnight Theatre in 1996, co-written by Wagner and Gaiman, which placed Dodds at the events of Dream's capture in Gaiman's The Sandman. In 2007 was the mini-series Sandman Mystery Theatre: The Sleep of Reason which featured Keiran Marshall briefly becoming The Sandman. Addtionaly, the series crossed over with James Robinson's Starman between issues #20-23, including art from Guy Davis and also with Wagner's own Madame Xanadu series.
The series is currently being collected in trade paperback form, years after its publication but it appears that Vertigo does intend to completely collect it eventually, slowly but surely.