We mark our years not only by the world's great events, but by the small tragedies and triumphs of our individual lives. These passages become mile markers, reminders of the days when part of us died and, in the bargain, we grew up a little.

David Darrow has crafted a deeply moving real-life fairy tale about one of these aching transitions in "The Passage, or What Comes of Searching in the Dark." Darrow wrote words and music about a hero's journey, in which a 12-year-old boy confronts the demons that threaten his sense of well-being and at the same time welcomes new relationships that bring hope.

Darrow's company, 7th House Theater, opened this poignant meditation on the loss of innocence Saturday at the Guthrie's Dowling Studio. A strong Greek chorus and a few lead actors play out the story of Albert Grissom, his friend Cassie, his noble mother and his mysteriously absent father.

Alejandro Vega plays Albert, a polite and self-possessed youngster who discovers Cassie (Mary Bair) in his backyard tent. She has just moved in next door, and companionship quickly fills the void they are each feeling. In a plot that could come out of a child's make-believe book, Cassie accompanies Albert as they confront the monster who is holding Albert's dad in the basement of his house. Lara Trujillo contributes a touching performance as the beleaguered mother.

That's all you need to know for now. It's worth the effort to see how it comes out.

Darrow and his cast have created a simple fable — told through the eyes of a kid who makes up adventures taking the garbage to the curb and dreams up fantastical characters. An eerie supernatural vibe occasionally cuts the sweetness, and the spare set contributes to the overarching atmosphere of loneliness.

Darrow's music recalls "Next to Normal" with its melodic and rhythmic patterns, banged out nicely by a small combo led by music director John Lynn on piano. The strong four-voice ensemble narrates the story with great accomplishment.

Keep the names of Vega and Bair in your memory. Vega first caught our eye a couple of years ago in Theater Latté Da's "Oliver," and last spring he portrayed Danny in Minnesota Opera's premiere of "The Shining." His character here requires a very light touch, and Vega is perfectly matched. Bair was Scout in the Guthrie's production of "To Kill a Mockingbird" last year. She, too, has a gift for stepping back and letting the character play itself through her.

7th House's last trip to the Guthrie was an unfortunate flub. This time, Darrow seems to have sacrificed a bit of his soul, and the young, likable professionals around him have pitched in to create a lovely small tale with a lot of heart.

Graydon Royce is a longtime Star Tribune theater critic. He can be reached at roycegraydon@gmail.com.