The Curious Incident of the Dog in the Night-time, SpeakEasy Stage Company, Roberts Theatre, Calderwood Pavilion, Boston Center for the Arts, through November 25. bostontheatrescene or 617-933-8600

There is something as curious about the play SpeakEasy Stage is currently staging at the Calderwood Pavilion as about a detail of the 1892 Arthur Conan Doyle short story "Silver Blaze" to which it alludes. The play in question, ''The Curious Incident of the Dog in the Night-time" by Simon Stephens, never actually refers to autism though protagonist Christopher Boone clearly seems challenged by Asperger's Syndrome. Many theatergoers at the Opera House tour press opening of this Tony Award winner earlier this year followed Christopher's singular odyssey with a standing ovation. Even so, this critic actually found the bark and bite of the intimate SpeakEasy Stage production more fully affecting than those of the striking tour.

Sherlock Holmes buffs may know that the legendary sleuth deduced that the dog in his case did not bark because it did not encounter a stranger. By contrast, the Swindon, Wiltshire dog Wellington in the title of the play and the 2003 Mark Haddon novel on which it is based does not bark because it is dead. Math savant Boone sets out Holmes-like to find its killer. Christopher's quest eventually challenges his social skills as well as his deductive powers. If Boone discovers the identity of the killer by the end of the first act, more personal mystery occupies his second act experiences. That more personal second act finds Christopher struggling with experiences that would rarely daunt other commuters-- namely, traveling on the British underground (subway), working with local maps and dealing with London streets. Eventually, Boone's accomplishments include doing very well on advanced math level testing as well as reaching his now London-based mother Judy and a pivotal moment of truth with his warring parents. A surprise gift from his father Ed elicits audience 'oohs' that savvy theatergoers may find somewhat kitschy, but Stephens play nevertheless stands tall as a call to understanding about not only autism but also respect for different perspectives about life and people.

This critic empathized more with Christopher and his journey as staged by SpeakEasy Stage artistic director Paul Daigneault at the Roberts Theatre-here reconfigured to give audience members more of a you-are-there experience. Christopher and Justin Swader's sets not only include the math detail-including extensive chalked formulas and Venn diagrams-- called for all around the performance space but also a grid-like backdrop for which designer Jeff Adelberg provides color-code lighting that matches and highlights aspects of Boone's odyssey as well as details connected with his parents, mentor Siobhan, Swindon neighbors and other people that either challenge him or support his efforts during the play. Essential to the production's insight-driven approach is Yo-El Cassell's choreographed movement -especially for ensemble players-that goes a long way to clarify Christopher's perceptions and actions in response to his challenges.

Director Daigneault sustains this clarifying approach with a strong cast. Purcell captures Christopher's on-going ordeal recording his successes and setbacks in solving the killing of the dog as well as navigating his way through the streets of London. He may not seem to shriek as frantically as Adam Langdon did as the tour's Christopher--a performance choice some may prefer-but this gifted actor's performance is fully convincing and involving. Jackie Davis has the right combination of warmth and tough love as paraprofessional Siobhan who guides Christopher in employing his own rhythms regarding society and his own behavior. Laura Latreille finds Judy's maternal caring as well as her weakness in relationships. Craig Mathers catches Ed's volatility and mitigating moments of feeling. Tim Hackney is properly unsympathetic as Judy's married romantic interest Roger. Versatile local talents Christine Power, Cheryl McMahon, Gigi Watson, Alejandro Simoes and Damon Singletary provide alternating tension and moments of humor in a variety of roles in Swindon and London.

In a signature moment of observation, Christopher admits, "I find people confusing." By contrast, Daigneault and company make his formidable odyssey in ''The Curious Incident of the Dog in the Night-Time" remarkably clear.