Curtains is a novell written by R. L. Stine. It was first published in 1990.
Description[]
Her terrifying secret was buried--until driven director Meritt Baxter tore it out of her during a performance. Suddenly Rena wasn't safe anymore. And the Merritt Baxter Summer Theater Camp had become a trap, where Bax would stop at nothing to elicit emotions that would lead to murder--onstage.