★★☆☆☆ Merrimack Repertory Theater, Lowell, MA. The Cambodian genocide perpetrated by Khmer Rouge constitutes man’s inhumanity to man at its nadir, and has already inspired memorable works of art including Lauren Yee’s shattering Cambodian Rock Band. Sam Chanse’s What You Are Now, on the other hand, is disappointingly flat. Chantrea (Sonnie Brown), a shellshocked survivor of the killing fields, has her hands so full with science prodigy daughter Pia (Pisay Pao), layabout son Darany (Joe Ngo, engaging if over the top in places), and adjusting to New England – Lowell has a large Cambodian community – that she has sublimated the horrors of her past. For reasons I didn’t quite catch, Pia resists pressing her mom to let the memories out. Instead, she seeks to help by researching ways in which science might blot out past fears, despite the reasonable argument of faithful beau Evan (solid, reliable Greg Maraio) that it could take decades to effect such a cure, whereas therapy is available a.s.a.p. Protagonist Pia is suffused with anger and ill-temper; I can’t readily recall a single moment of lightness or humor in Pao’s portrayal under Steve Cosson’s direction. Surely Pia should try. Her mood is only darkened when Darany gets caught up in an immigration mess, all of which makes for 90 minutes of slogging dramaturgy. At the end, again for reasons I didn’t understand, Pia does opt to urge mom to open up, resulting in a beautifully rendered monologue by Brown that almost redeems all the rest. Chantrea’s memories serve as evidence that all too often, what you are now is far less compelling and moving than what you were then. Runs through May 11. www.mrt.org. (Photo of, l-r, Ngo, Brown and Pao by Meg Moore.)