Extreme grief turns the world upside down, sideways, totally out of order. And the most terrible heartbreak of all must be the loss of a young child.

Suburbanites Becca and Howie respond to their pain differently after their beloved 4-year-old chases his dog into the street and is accidentally hit by a teenaged driver who fails to see him. But in both cases, the world has become skewed, thus the “Alice in Wonderland” title reference, “Rabbit Hole.”

Playwright David Lindsay-Abair wrote about how his perceptions changed after he became a parent. His previous quirky plays (“Fuddy Meers,” “Kimberly Akimbo,” etc.) about off-center women coping with crisis have won awards but his characters were not quite real, but this time they are. Winner of the 2007 Pulitzer Prize, “Rabbit Hole,” clearly directed by Christy Montour-Larson, is delicate and moving, although there are touches of humor and it ends on a note of hope.

It’s the kind of rich play Curious Theatre does with real skill.

Becca and Howie , beautifully played by Rachel Fowler and Eric Sandvold are very real: stunned and seeming to have a wall between them. Tight and reserved, afraid of letting feeling show less she dissolve, she has put away all the photos and we meet her folding tiny clothes to give to charity. She has given the dog to her mother and he really wants it back. She resists any attempt toward affection from Howie and is indignant at the platitudes she hears from friends, but resentful when they fail to call. Emotional Howie goes to a grief group and watches a home video of their son and his dog to console himself, until she tapes over it— accidentally? He verges on exploding.

It’s been eight months when the lights go up on their tidy, pastel home. Becca’s lively, unconventional younger sister Izzy (Jessica Robblee) is visiting and tells Becca she’s pregnant— and that their mother is pleased, despite no wedding ring. We later learn that mother Nat (Kathryn Gray) also lost a little son and still grieves many years later… “it’s what you have…”. Nat is an interesting mix of flaky and wise.

The final character is the 18-year-old driver Jason (Sean Mellot) who appears unexpectedly, fully recognizing that he is at fault, and needing to talk. Howie erupts, but Becca feels strangely maternal and does talk with him later, learning about the prom and graduation she’ll never experience.

Lindsay-Abair’s language throughout is right on.

“Rabbit Hole” by David Lindsay - Abaire is presented through Feb. 14 at Curious Theatre, 1080 Acoma St., in Denver’s Golden Triangle. Performances: 8 p.m. Thursdays, Fridays, Saturdays; 2 p.m. Sundays. Tickets: $34, $27, 2 for 1 on Thursdays. 303-623-0524, www.curioustheatre.org.