Natalie Portman shines in "Impossible" film

Actress Natalie Portman listens during a news conference for the film ''Love And Other Impossible Pursuits'' at the 34th Toronto International Film Festival September 16, 2009.

TORONTO (Hollywood Reporter) - Natalie Portman impresses mightily in "Love and Other Impossible Pursuits," playing a second wife and grieving first-time mother grappling with the thorny complexity of family dynamics.

The Don Roos vehicle that showcases the accomplished performance is somewhat less so, hampered by a structure that initially makes the proceedings tricky to follow. It ultimately finds its footing, but it's Portman's skillfully executed turn that deserves pursuit by a distributor who knows its way around an awards campaign.

Based on Ayelet Waldman's Manhattan-based novel, the tart dramedy wastes little time in setting up the strained relationship between Emilia Greenleaf (Portman) and her precocious stepson, William (Charlie Tahan), the product of his father Jack's (Scott Cohen) previous marriage to the caustic, fiercely overprotective Carolyn (Lisa Kudrow).

But if her being regarded in certain circles as a home-wrecker might be explanation enough for her glib view of the universe, there's a deeper reason for that emotionally aloof defense mechanism.

The death of the 3-day-old child she had with Jack has left an increasing void in her life that threatens to swallow up everyone else who cares about her. While this might sound like awfully heavy stuff, Roos has a proven gift for finding humor in some unlikely places, most notably (and still most successfully) in his 1998 directorial debut, "The Opposite of Sex."

Achieving that balance is not the problem with "Impossible Pursuits"; rather, it's an often-confusing series of subtle flashbacks early on that sometimes makes it challenging for the viewer to sort out the past from the present.

When Roos dispenses with the time shifts and takes a more linear approach, the film settles in to a more focused, more affecting groove.

But while he draws fine work from all concerned, including Debra Monk and playwright-actor Michael Cristofer as Emilia's parents, it's Portman who you simply cannot take your eyes away from, and not for the obvious reasons.

With her brittle, risk-taking performance, Portman officially has grown into her potential as an actress of commanding depth and versatility.

(Editing by DGoodman at Reuters)