This gritty and absorbing 2000 feature by Spanish director Achero Manas opens with a taut sequence in which schoolkids play chicken in a railroad yard, racing from either side of the track to grab a bottle of water just before a train arrives. The same dynamic plays out in the story, as young Pablo--nicknamed "El Bola" for the ball bearing he carries around--befriends Alfredo, a fellow outcast at school, and Alfredo's dad enlists the help of a social worker to rescue Pablo from his hateful and abusive father. Written by Manas and Veronica Fernandez, this is quick and unpredictable storytelling, its dialogue simple but tough. Alberto Jimenez is excellent as the conscience-stricken father, whose duty to respect the law tests his relationship with his own son, and both kids, Juan Jose Ballesta and Pablo Galan, give passionate, committed performances. With Manuel Moron. 88 min. Gene Siskel Film Center, 164 N. State, Friday, December 13, 6:15 and 8:15; Saturday, December 14, 4:15 and 8:15; Sunday, December 15, 4:15 and 6:15; and Monday through Thursday, December 16 through 19, 6:15 and 8:15; 312-846-2600.