“Highway Patrol” runs through Feb. 18 at the Goodman Theatre. (Courtesy of Goodman Theatre)

Secrets and lies hide in plain sight in “Highway Patrol,” a can’t-miss mystery at the Goodman Theatre.

It tells a true story centered around a puzzle that seems easy enough to solve. As the mystery morphs and raises new questions, it makes for a riveting evening of storytelling.

Actor Dana Delany portrays herself. She directly addresses the audience and details her correspondence on social media with a precocious 13-year-old boy recovering from a heart transplant.

The text is based on the actual tweets, messages and emails between Delany and the boy, Cam. Delany shares Cam’s photo — he’s a sweet kid with serious health issues who lives with family in Costa Rica.

Delany feels good about the blossoming friendship. She buoys the boy, and he fills a void in her busy life. He’s funny, charming and only occasionally inappropriate as he declares his love for her.

But humor and sweetness soon give way to something darker. When Cam says he communicates with dead people, the mood quickly chills. Paranoia begins to creep.

Delaney is onstage for much of the show. She’s a likable and vulnerable guide to this strange chapter in her life, and she is joined by two actors. Dot-Marie Jones (“Glee”) gives a standout, multifaceted performance, and young Chicago actor Thomas Murphy Molony ably plays the smitten boy.

“Highway Patrol” runs through Feb. 18 at the Goodman Theatre. (Courtesy of Goodman Theatre)

Delaney is best known for TV work, including portraying a nurse on “China Beach,” a “Desperate Housewife” and a doctor on “Body of Proof.”

“Highway Patrol” is like an episode of “Unsolved Mysteries” made by the producers of “This American Life” and starring an actor who isn’t a doctor but played one on TV.

Delany co-created the show with writer Jen Silverman, director Mike Donahue and set designer Dane Laffrey. They deliver a wild ride, despite some confusing transitions and decisions that feel arbitrary, including the title. There’s nothing here a skilled script doctor couldn’t solve.

And if the play doesn’t end with a neatly tied climax, that only makes it more real. It raises complex emotions and asks big questions: Does compassion make us vulnerable? How important is connection in the face of deceit? Should I change my passwords when I get home from the theater?

“Highway Patrol” is at the Goodman Theatre, 170 N. Dearborn St., through Feb. 18.