I've been a huge fan of People's Light & Theatre Company's Family Discovery Series since its inception with the stirring Hush: An Interview With America in 1996. Since then, a mixture of ambitious adaptations and new plays for families—some for little kids, some for more mature audiences—have defeated the limiting "children's theater" label with uncompromised production values, first-rate acting and sensitive, positive plays.

This year's series, however, reveals a disturbing slide toward mediocrity, a mission mushiness that might drive away loyal audiences. It's not that PLTC has devolved into traditional children's theater—even their new holiday tradition, an adaptation of the English pantomime style, superbly reimagines fairy tales like "Jack and the Beanstalk" and "Sleeping Beauty"—but that recent plays, like last fall's Jason And The Golden Fleece and the current Yemaya's Belly, are uninspiring choices that examine myth without magic or mirth.

Yemaya's Belly, by West Philadelphian Quiara Alegría Hudes, is downright grim. The always charming Mark Del Guzzo plays 12-year-old storyteller Jesús, who lives in an impoverished Caribbean village. Adults Tico (Joe Guzmán) and Uncle Jelin (Michael Cruz) instruct him in bland platitudes ("When you're a man, you learn to pay"), but his life seems aimless until his parents (whom we barely meet) die in a fire.

The orphan ventures to a city, where he's befriended by a shopkeeper (Mary Elizabeth Scallen), who also instructs him ("Nothing is free"). He meets Maya (Joanna Liao), a girl of indeterminate age who offers to take him to America. He steals supplies from the shopkeeper and the two kids depart in a tiny boat.

Jesús' story is sad, but in Shannon O'Donnell's production, also uninvolving and tedious. Del Guzzo wrings a little comedy from Hudes' script—which seems more about a young man's sexual awakening than a Family Discovery Series production can comfortably express—but connections and motivations never develop convincingly.

Most discomforting is Jesús' naive view of America as a welcoming paradise. Given today's immigration debate, this is especially ironic; when Jesús imagines "the president of America" as a beneficent prince greeting him with open arms, we know he's in for a rude awakening.

Yemaya—a Santeria sea goddess—isn't introduced until late, when we learn that Maya is an orphan, too. The characters' lives aren't open to us, so their grief (like Tico mourning his wife) is distant, unconvincing and—in a way that's always deadly, but especially for a play attended by children—boring.

The spring Family Discovery Series production used to be directed at younger children, with plenty of fun for audiences of all ages, even while tackling serious subjects. Yemaya's Belly, unfortunately, doesn't seem directed for anyone.

YEMAYA'S BELLY Through May 7, People's Light & Theatre Company, Rt. 401, Malvern, 610-644-3500 or www.peopleslight.org