“Tell me it’s not true. Say it’s just a story.”

Willy Russell’s heart-wrenching musical “Blood Brothers” shocks and entertains through June 18 at The Pennsylvania Playhouse, Bethlehem.

The tragic story of the Johnstone twins separated at birth, one raised in prosperity and the other in poverty, is told through lovely music and an engaging narrative. The cast, directed by Bill Mutimer, gives emotional and vocally-strong performances. The musical’s book, lyrics and music were written by Russell.

Heather Reese portrays Mrs. Johnstone, the single mother of seven children. Because of her desperate financial circumstances, she is intimidated into promising one of her unborn twins to her wealthy, childless employer, Mrs. Lyons. Reese carries the emotional weight of the show and her low, clear voice fits the role beautifully.

Ian Gilkeson and Thomas Kennebeck play twins Mickey Johnstone and Edward Lyons, respectively. The actors handle the challenge of portraying the boys at ages 7 and 14, as well as adults remarkably well. Their childish mannerisms and imaginative playing are believable. Gilkeson’s journey from mischievous boy to troubled adult is captivating. Kennebeck’s voice is impressive and his inner conflict is evident.

Rody Gilkeson gives an enthralling performance as the narrator. Not just a passive storyteller, he interacts with the characters and alternates between eerie narration and powerfully-belted warnings that drive the story.

Elizabeth Marsh-Gilkeson and Seth Rohrbach are stuffy and pretentious as the well-off Lyons. Marsh-Gilkeson develops a complex character that begins to unravel. Rohrbach is convincing as the self-absorbed businessman.

As Linda, friend and sweetheart of the twins, Taylor Van Kooten charms with energetic sass. She matures into a caring young woman who is torn between the two brothers.

Tyler Fernandez is devilish as Sammy, Mickey’s troublesome brother. Mary Catherine Bracali, Hannah Cummings, Cindy Ernst, Matt Hogan, Sherilyn Jones, Dominick Philip, Michael Pizolato and Kristofer Swanson complete the ensemble in playing numerous roles. The group musical numbers are stirring and blend well. The distinct characterizations lend believability to the siblings, friends and townspeople.

The opposing socio-economic backgrounds come to a head in the thrilling final scenes of the show. The outcome leads one to wonder about the power of superstition and the influence of class standing.

Mutimer’s direction adds some fun movement and keeps the scenes flowing into each other nicely. The purpose of each scene in the dramatic story is clear.

Set and lighting design by Brett Oliveira are well-executed. The set is minimalistic and industrial and conveys working class and wealthy homes. Lighting is superb and adds to the dramatic tension.

Todd Burkel’s costuming highlights the class differences and stands out well against the rugged set.

Sound design by Patrick Moren includes well-placed echoes and pulsing beats that increase the intensity.

Nicole Keefe stage manages, Matthew Trovato is music director, and Steven Rosenblum and Brian McDermott are technical operators.

“Blood Brothers” is recommended for audiences 12 and up.

Tickets: Illicks Mill Playhouse, 390 Illicks Mill Road, Bethlehem; paplayhouse.org; 610-865-6665