Be My Oswald (2006)

A militant vegetarian, known as B, recruits a clueless socialite activist, known as A, for a holiday mission that might change the world. They communicate via phone and fax as A completes a precise list of tasks in preparation for their big event. Unannounced, B joins A at the space the evening before the parade and forces A to make her formal commitment to the mission. A bloody robbery involving a neighbor and an impulsive move from A dealing with a catered Thanksgiving breakfast threaten to compromise B's time sensitive plan. As B makes her final preparations and her intent to assassinate Santa Claus becomes clear to A, a life or death struggle ensues as Santa Claus makes his grand entrance, quite possibly for the last time.