Comtra Theatre, Route 19 in Cranberry Township, presents "Arsenic And Old Lace" opening Friday and continuing through April 24. The classic comedy tells the story of the Brewster sisters, who did a "charity" of poisoning lonely old men to save them from their loneliness and then burying them in the basement. Curtain is at 7:30 p.m. Fridays and Saturdays. Admission is $12 for plays and $15 for musicals. Box office opens at 6:45 p.m. the day of the show. Call 724-773-9896.

<B>Kean Theatre,</B> 5847 Meridian Road, Gibsonia, presents "Doubt: A Parable," an award-winning drama by John Patrick Shanley, Fridays and Saturdays from April 16 to 24. Curtain is at 8 p.m. April 16, 17, 23 and 24. Cost is $22 for a show only or $41 for a show and dinner at any of the Atria's Restaurant & Taverns. A matinee is set at 2 p.m. April 18 for $20 for show only or $39, which includes show and lunch at the Mount Vernon Restaurant, located in the same building as the Kean Theatre. Tickets are available by calling 724-444-5326 or by visiting www.keantheatre.com.

<B>Pittsburgh International Children's Theater</B> presents Fred Garbo's Inflatable Theater Co. for three performances at the Byham Theater, 101 Sixth St. Shows begin at 2 p.m. Saturday and at 11 a.m. and 2 p.m. Sunday. Tickets are $11. Call 412-456-6666 or visit www.pgharts.org."<B>August: Osage County,"</B> Tracy Letts' 2008 Tony Award- and Pulitzer Prize-winning play starring Academy Award winner Estelle Parsons, runs through Sunday at the Benedum Center, 719 Liberty Ave. The play tells the story of the Westons, a large extended clan that comes together at their rural Oklahoma homestead after the alcoholic patriarch disappears. Tickets range from $21 to $55 and are available by calling 412-456-6666 or online at www.pgharts.org.<B>CLO Cabaret</B> is presenting "Nunsense," through June 6 at the CLO Cabaret at Theater Square, 655 Penn Ave. Performances begin at 7:30 p.m. Wednesdays through Saturdays, at 2 p.m. Saturdays and Sundays and at 1 p.m. select Thursdays, with some exceptions. Tickets are $39.50 for Wednesday, Thursday and Friday evenings, $44.50 for Saturday evenings, and $34.50 for matinees. Call 412-456-6666.