The Repertory Theatre of St. Louis has an annual series called “Ignite!” It consists of three new plays, still works-in-progress, which are presented in a rehearsal hall without costumes or sets. The actors rehearse for a few days, then read it from looseleaf notebooks on music stands. The playwright, who often has been making changes right up to showtime, is in the room, taking notes on the audience’s reaction as well as the Q and A conducted by director Seth Gordon afterwards. Presumably, the instant focus-group-like responses from the crowd of about 150 will steer the author through yet another rewrite of their work.

My wife and I have attended several of these readings over the last five years, but on Saturday, we saw the best of the lot. It’s called “Replica,” by Mickey Fisher, whose work includes the Fox TV series “Extant,” which starred Halle Berry but, ironically, is extinct as of last September.

“Replica” is a story from our near future about a woman who has a terminal disease and has checked into a facility where everything about her will be duplicated in an exact copy — her looks, her mannerisms, and her memories — so that her children won’t grow up without a mother. Finding talented twin actresses to play the lead roles might sound like a casting challenge, but Gordon explained that with wigs and makeup (and an audience that suspends disbelief enough to meet them halfway), it’s not an impossible task.

Fisher’s script is taut, witty, emotional, and suspenseful. I won’t give away an iota of where the plot takes you, but my wife and I were both riveted. Afterwards, we told Fisher how impressed we were, and that he shouldn’t change much, if anything. I even referred to “Replica” as “Philip K. Dick / Rod Serling great.”

Sometimes, the plays that are read at Ignite go on to full productions, like “Soups, Stews, and Casseroles: 1976” and “Molly’s Hammer” (which we heard a year ago and is about to hit the mainstage at The Rep). I hope that we’ll get to see a full stage production of “Replica,” because even though we know what happens, it’ll be interesting to see how Fisher has tweaked it — and how that casting thing works out.

Beyond that, I root for good theater to blossom so that others may enjoy it, too. “Replica” is one that deserves a wide audience.