Titled In The Vale Of Health, the cycle comprises Japes, Japes Too, Michael and Missing Dates, and will run in the Hampstead Downstairs from 20 March to 17 May 2014.
The four plays are based on the same characters - two brothers who fall in love with the same woman following the death of their parents - but telling different stories with opposite conclusions.
The cycle began when, watching rehearsals for Japes ahead of its West End premiere in 2001, Gray realised the characters might have made different choices and arrived at a different outcome.
Gray, who died in 2008, described the plays as featuring "the same characters in the same situation in the same house, but telling a slightly different story through to an almost opposite conclusion, or to the same conclusion but by an unexpected (at least by me) route."
Directed by Tamara Harvey (The Kitchen Sink, From Here to Eternity), In The Vale Of Health will run in rep, with casting still to be announced.