William Earl “The Gray House,” the Kevin Costner-produced limited series about a female spy ring during the Civil War, will open Monaco’s 63rd annual Monte-Carlo Television Festival in June. The six-episode limited series tells the hidden-history tale of four Southern women — a Virginia socialite and her mother, a formerly enslaved Black woman and a high-end prostitute — who served as key espionage agents for the Union. The foursome are credited as unsung heroes who helped end the nation’s brutal cleavage in 1865.