Andrew Keenan-Bolger, left, and Sarah Charles Lewis in “Tuck Everlasting.” (Joan Marcus)

NEW YORK — Despite a boatload of talent, "Tuck Everlasting" remains marooned in kiddie harbor. This stage musical version of Natalie Babbitt's bestselling children's novel tells of a family living (and living and living) under a special charm that turns out to be a special curse. And yet the show itself, under Casey Nicholaw's direction, comes across as not special enough.

As in the far more engaging story of Peter Pan, this one introduces your little ones in a gently consoling way to the concept of mortality. The vehicle is the Tuck clan, whose members (Michael Park and Carolee Carmello as the parents; Robert Lenzi and Andrew Keenan-Bolger as their sons) once upon a time drank from a magic spring that conferred on them immortality. This makes them lonely, not happy, because everyone else they come to know — except their cat, which also partook of the waters — grows old and dies.

It's better, "Tuck Everlasting" avers, to savor each moment of a finite existence, than to muddle through the fatiguing immutability of a lifetime that rolls on ad infinitum. It's a perfectly apt lesson for the second grade set. But because so much of the show concerns the burden the Tucks have to live with, the score by Chris Miller and Nathan Tyler leaves little more than a mournful impression, and the workmanlike book by Claudia Shear and Tim Federle oozes sincerity rather than real humor or pathos. The overall effect — despite the skills of Broadway pros like Park, Carmello and Keenan-Bolger, not to mention such other dependable vets as Terrence Mann and Fred Applegate — is leaden.

The musical, which had its official opening Tuesday night at the Broadhurst Theatre, no doubt can count on a future as a staple of companies that cater to young audiences. The Broadway incarnation, decked out in pretty, storybook sets by Walt Spangler and Gregg Barnes's lovely costumes,  features 11-year-old Sarah Charles Lewis as Winnie Foster, the vivacious New Hampshire girl who's chafing under the constraints imposed on her by her widowed and eternally grieving mother (Valerie Wright).

Sarah is technically accomplished, with a strong, clear voice and the fortitude necessary to carry the central role in a Broadway show.  Many of the young girls you take to "Tuck Everlasting" will surely want to be her, even if adults might prefer to be somewhere else.

Tuck Everlasting, book by Claudia Shear and Tim Federle, music by Chris Miller, lyrics by Nathan Tyler. Directed and choreographed by Casey Nicholaw. Sets, Walt Spangler; costumes, Gregg Barnes; lighting, Kenneth Posner; sound, Brian Ronan; orchestrations, John Clancy; music direction, Mary-Mitchell Campbell. With Pippa Pearthree, Michael Wartella. About 2 hours 15 minutes. Tickets, $59-$225. At Broadhurst Theatre, 235 W. 44th St., New York. Visit telecharge.com or calls 212-239-6200.