Vaguely uninviting, not-funny-enough touches begin with the opening scene, in which the older Rudy (Tom Wilkinson) is enjoying an old-time sexploitationer in a cinema (what kind of venue is this supposed to be, exactly, a porn revival house?) and trying to force his younger companion, Henry (Billy Crudup), who's averting his eyes, to watch with him. Seems this sort of diversion helps the pair cook up ideas for their ongoing collaboration on children's books, and it works this time, as they successfully pitch their idea for a tome about beavers to their editor, Arthur (Bob Balaban).

The first "Marty the Beaver" book evidently hits big, but when the robust Rudy suddenly dies, writer Henry is matched with new illustrator Lucy (Moore), a good-looking kid with issues stemming mostly from her nutsy mother (Dianne Wiest).

Henry does everything he can to alienate Lucy, insulting her and providing a crash course on his antisocial neuroses. But the financial incentives are too great to ignore: Henry's book contract will be canceled unless he produces in 3½ weeks, while Arthur privately promises Lucy a $200,000 bonus if she can get Henry to deliver.

As they launch their collaboration, Henry's quick-trigger nastiness remains in excellent working order. But the nastiness is just a defense system for his insecurities; in periodic visits to Rudy's grave, he admits to his departed mentor that he's beginning to like the young lady who, in a bit of inconvenient timing, is again being courted by the former beau who once dumped her (Martin Freeman).

An off-season spell together in Arthur's spacious Long Island manse is intended to force Henry and Lucy's book to completion, but it also forces the issue of their relationship, for better and worse. Henry unsurprisingly turns out to be a romantic at heart, but he's his own worst enemy when anything important is on the line.

Henry's willful orneriness dominates David Bromberg's screenplay, which fitfully develops a romantic subcurrent that Crudup is able to illuminate at certain moments. But Theroux doesn't maintain firm control of the tone, particularly going astray in attempts at comic interludes as well as in the ending, which unattractively takes place in a public bathroom and is not really convincing in the bargain.

Moore is perfectly all right, but it would have been nice to see Lucy at work on occasion to show her artistic skills. When all is said and done, one is never persuaded that she belongs with either Henry or her old b.f.

Tech contributions are good, although pic could lose some of the music-filled interludes to quicken the pace.

Camera (Technicolor), Steve Kazmierski; editor, Andy Keir; music, Edward Shearmur; additional music, Deerhoof; music supervisor, Tracy McKnight; production designer, Teresa Mastropierro; set decorator, Niamh Byrne; costume designer, Heidi Bivens; sound (Dolby Digital), Ken Ishii; sound designer-supervising sound editor, Ben Cheah; re-recording mixer, Lewis Goldstein; associate producer, Jessica Levin; assistant director, Mariela Comitini. Reviewed at Sundance Film Festival (Spectrum), Jan. 24, 2007. Running time: 111 MIN.