After telling an anti-mime story, Jon Spelman does the decent thing: He notes that it's easy to be snide about bad art. Then he adds, rather pointedly, "Some people get paid to do it." Yes, they do. It's that kind of world. But they get paid to be snide about bad art, not about the sort of thing Spelman is doing so engagingly in his one-man show "On the Bedpost Overnight" at the Woolly Mammoth for the next two Monday and Tuesday nights.

Spelman bills himself as a storyteller, but he's looser and more conversational than the word implies. He's been compared to Garrison Keillor, but Keillor is a showman -- a stylist of homeyness. Spelman is a rumpled presence, about as non-"theatrical" as you can get. He gives the impression he's not quite comfortable up on the stage, that given his preference he'd sit down among the audience he's addressing.

Basically, Spelman just talks. Being with him is like being part of an extremely entertaining after-supper, into-the-wee-hours conversation. Spelman does all the talking, of course, but his pauses, lack of assertiveness and sensitivity to the audience's reactions give "On the Bedpost Overnight" the feeling of give-and-take.

What does he talk about? Oh, life. Et cetera. At 48, he's the father of a 2-year-old girl and he can't quite get over it. In the beginning of his talk about Anna, the audience may think -- snidely -- that they're in for one of those starry-eyed evenings about the Wonder of Life, the sort of thing that makes you feel guilty because you're not as sunny and appreciative as the Wonderer. Well, Spelman has a lot of wonder, but he has apprehension too, and uncertainty, and regret. Plus he's very funny.

He makes humor, for example, out of the unlikely material of parents' anxieties about their small children, describing a "Baby Life" course taught by a helpful idiot named Noel. "Here are some of the ways your little infant ... can die," Noel announces chirpily, then invites his students to "Take a crawl through your home -- see how many ways you can injure yourself." Noel is full of unnerving, useless information, things like "The most children are killed when they are dropped." How is a parent supposed to respond to this? I'll never hold my child again! Spelman isn't a sick humorist here. His jokes aren't about injured children but about our helpless need to protect children, and how even if we laugh at that need, our fears remain.

A proud, worrying, middle-aged parent, Spelman (who was for three years host of the children's television program "Three Stories Tall") is also still a child, bringing his mother and father to vivid, troubling life for us. He tells a story about spending a weekend at a monastery with his father. It's a funny story, but in the middle of it his father, inexplicably, throws a rock at him and cuts his face open. Spelman leaves this incident unadorned. He never tells us whether it was deliberate or accidental, or even whether his father ever apologized. At this point, the show begins to turn mysterious: sad but slightly dreamlike, like memory. "My parents were both suicides of a particular kind," Spelman confides simply. His mother smoked even while on oxygen for her emphysema. His father, trapped in an unhappy second marriage to a woman Spelman describes as "the wicked boring stepmother," developed a brain tumor that ultimately killed him. After he died, Spelman took custody of the ashes from the stepmother, and was appalled when he examined them to find not feathery gray ash but sand and bits of bone: "These were the remains of a meal! A picnic on the beach!"

Beneath his seeming rambling, Spelman has a literary consciousness. Images recur with different meanings throughout "On the Bedpost Overnight," particularly the Black Hole -- which is first a scientific phenomenon, then a metaphor for a time Spelman fainted, then a knothole on the wall of his bedroom that frightened him when he was a child. It shadows the stage, this Black Hole, and finally, when Spelman gives an extraordinary account of a fatal car crash he witnessed, it takes on its deepest meaning. Death hovers at the edges of this wonderful life. Will it claim your child? How will it claim your parents? When will it claim you? "I now know," Spelman says, referring to the scary knothole, "that what will reach out and snatch me out of my bed ... is time."

The simultaneous excitement and limitation of Spelman's kind of art is that it reduces the theatrical experience to the personality of the performer. Comedians are known for their existential fears of going onstage: "I'm gonna die out there tonight!" For the storyteller, without the safety net of gag lines, things are even riskier. And he's really taking a chance when, like Spelman, he's not in-your-face but willing to give you a chance to make up your mind about him. Spelman sidles up to you like a cat, revealing himself gradually. You start out laughing at a friendly jokester and end in appreciation of a mystical poet.

On the Bedpost Overnight, written and performed by Jon Spelman. Consulting direction by Howard Shalwitz. At the Woolly Mammoth Theatre, 1401 Church St. NW, Feb. 4, 5, 11 and 12.