I suppose the acid test of the quality of any production of “The Miracle Worker” is whether a tear runs down your cheek when Helen Keller finally discovers nouns at the water pump.

By that standard alone, Torch Theater’s third staging of William Gibson’s play is a gushing success. For that, thanks go to a phenomenal 10-year-old actress named Scarlett Thompson who makes the wild child a desperately believable creature whom we desperately want to bloom.

Moreover, the production that opened in St. Paul last weekend in the History Theatre rides sturdily on the shoulders of Stacia Rice, who now wears the role of teacher Annie Sullivan like a second skin. When Annie and Helen are together, the show has a magical crackle, especially during the wonderfully choreographed food fight in the dining room.

Even so, when Annie finger-spells “I love Helen” to the child in the final scene, you suddenly realize — hey, the kid already has a grasp of a first-person pronoun and the verb use of the most-discussed four-letter word in the English language. Talk about a quick study!

Yeah, it’s a creaky, manipulative play, but director Craig Johnson has pared it down to a smooth two hours with intermission. In the secondary roles, Jody Briskey and Clark A. Cruikshank give a heartfelt glow to Helen’s parents — though Cruikshank downplays the post-antebellum imperiousness of the father and that makes the somewhat thankless role of his estranged son (Randy Schmeling) all the more thankless. Linda Sue Anderson hits all the right notes as the fussy aunt who is there to provide laughs or groans with mostly stupid, thoughtless comments.

This production is well worth seeing for the quality of the work and, especially, if you need your heart tugged during our bleak winter. Perhaps unavoidably, it’s also very earnest. I attended opening night, when the audience was full of friendly actors who traditionally howl at every funny line, real or imagined. There were some laughs — Cruikshank is particularly adept at wringing them — but mostly this was serious business.

There’s always something compelling about a play that embraces the triumph of the human spirit and the support of loving, dedicated hearts. The play runs through Feb. 21. For information, go here.