Sentimentality comes with any story about a dying high school boy's last wish. Yet "One Last Thing . . ." - which is buoyed by performances by Cynthia Nixon as the care-worn mother, Karen, and Michael Angarano as the determined-to-live-until-the-end son Dylan - never becomes mushy.

Michael and Cynthia Nixon Credit: Magnolia

From the first scene, with its acknowledgement that these are Dylan's last days, "One Last Thing . . ." tries for a matter-of-factness to undercut the sadness. The doctor (Brian Stokes Mitchell) is concerned but frank.

Dylan is to participate in a Make-A-Wish-style program. His wish is to go fishing with his favorite football player (a restrained, low-key and right-on Johnny Messner), but before the ceremony he gets stoned on medical marijuana. Then live, on camera, Dylan blurts out that he wants a weekend with supermodel Nikki Sinclair (Sunny Mabrey).

Sunny Mabrey as a supermodel Credit: Magnolia

What sounds like a Disney movie gets grittier since Nikki is, in her own words, a bitch, a boozer and self-destructive. Angarano's chipmunky charm is neatly balanced with conflicting fear and resignation, and Nixon shows yet again how, without any Eleanor Roosevelt prosthetics or "Sex and the City" glam, she is one of the best.