Tangled-up tale of immigrants in L.A.

In the aerial shots of Los Angeles that punctuate Wayne Kramer's Crossing Over, the cloverleaf created by intersecting freeways gives the impression of embroidery on fine cloth.

Once the director gets down to ground level, though, the picture looks markedly different. Looking from L.A. south to the Mexican border, Kramer sees immigrants - many of them undocumented and anxious to become legal. And he shows how they try to weave into the social fabric and in the process get all tangled up.

So, too, does Kramer's film, a responsible message movie wrapped in an irresponsible exploitation flick that cries fire in a crowded theater.

A feverish, multistory affair cut from the same bolt as Crash and Traffic, Kramer's Crossing Over presents Southern California as an unraveling crazy quilt of a big tent. For every foreigner desperate to get in, there is a gatekeeper preventing it - or profiting from it.

Similarly, in Kramer's obviously heartfelt movie about the risks many take to be in America, for every gripping plot turn taking you to the edge of your seat, there's one that has you shaking your head in disbelief.

Harrison Ford - in his best role in years - and Cliff Curtis are the main reasons to see the film. They play Max and Hamid, ICE (Immigrant and Customs Enforcement) agents whose job is to pull out illegals like so many stray threads. They raid sweatshops and take into custody undocumented workers such as Mireya (Alice Braga). If she gets deported, who will care for her young son?

Also in Kramer's patchwork are U.S.-raised children of immigrants, like Taslima (Summer Bishil) and Yong Kim (Justin Chon), who try to reconcile divided identities. If they assimilate, they become alienated from their families. If they are proud of their countries of origin, they don't fit in with their native-born peers. Taslima, who gives an impassioned classroom speech interpreted by some as Osama bin Laden propaganda, also arouses the suspicion of federal agents.

And trying to stake a toehold are aspiring actors and singers (and sometimes lovers) Gavin (Jim Sturgess), from Britain, and Claire (Alice Eve), from Australia. In their attempts to score green cards, one games the gatekeepers and the other is gamed by them.

Every drama needs a villain. This overstuffed melodrama has two. One is an Immigration and Naturalization Services adjudicator (Ray Liotta), who trades legal status for sexual favors. The other is . . . well, that would be giving away too much.