Sunday is a day of rest, generally the least eventful day of the week. Filmmaker Jonathan Nossiter, however, has constructed a Sunday of a very different stripe, one on which people collide in intriguing and unexpected ways. Sundays hold little significance for Olive (David Suchet); a former IBM employee left homeless by a layoff, he finds it just another day to kill until returning to the shelter where he sleeps. But when he crosses paths with Madeleine (Lisa Harrow), a high-strung actress who is no longer young, she mistakes him for a famous director. Attracted to her and flattered, Oliver plays along; he becomes "Matthew Delacorta" and spends the day with her. Together, these two slightly off-kilter people develop a fantasy--or is it a folie a deux?--in which both can hope for career and personal redemption. But Madeleine's estranged husband (Larry Pine) and the other men who share Oliver's shelter present forces of reality that threaten to sour this fragile accord. One of "Sunday's" strengths is that the audience can never tell whether Madeleine and Oliver are doing something healthy or dangerous together; one is constantly unsure of what will happen next. Powerfully honest and risky performances from Suchet and Harrow propel the film, which provides as bleak a view of the streets and row houses of Queens as may be imagined. Writer/director Nossiter, in his debut feature film (he previously helmed the well-received documentary "Resident Aliens"), shows a deft touch with suspense, character and milieu. "Sunday" is a film filled with small pleasures: a lovely scene in a Greek Orthodox church; an exchange of stories between the leads in which truth takes on the power of fiction. Ultimately, this thought-provoking work adds up to a unique and memorable experience, one well worthy of the two awards it took at Sundance. Starring David Suchet, Lisa Harrow and Jared Harris. Directed by Jonathan Nossiter. Written by James Lasdun and Jonathan Nossiter. Produced by Jonathan Nossiter and Alix Madigan. A CFP release. Drama. Unrated. Running time: 92 min. Screened at Cannes.