From the liner notes

A contemporary drama set in Washington, D.C., The Walker centers around Carter Page (Woody Harrelson), a gay, well-heeled and popular socialite who serves as confidant, companion, and card partner to some of the capitol’s leading ladies. The character is supposed to be modeled after Truman Capote (before he became a drunk). These pampered women are married to the most powerful men in America, and when their husbands are too busy running the country to attend to their wives, they turn to their "gay best friend," Carter, for warmth, wit, and wisdom. Carter’s loyalty is tested when his dearest friend (Kristen Scott Thomas) finds herself on the brink of a scandal that could destroy her reputation and her husband’s career. Offering to cover for her, Carter suppresses incriminating evidence, only to find himself the chief suspect in a criminal investigation. Suddenly, this well-connected man-about-town is a pariah, hounded by the police and forced to find the true culprit and clear his name. He seeks help from an ex-lover Emik Emek (Run Lola Run's Moritz Bleibtreu) who helps restore his reputation. More importantly, he must re-examine whether it is important to be accepted by a society based on betrayal, hypocrisy, and corruption.

A tale of moral redemption that takes the form of a mystery-thriller, The Walker is the third part of Schrader’s "lonely man" trilogy that began with American Gigolo (1980) and also includes Light Sleeper (1992).