When a man dressed as Santa Claus blows himself up during a botched bank robbery, Brennan and Booth work to identify the bomber and determine his motives. Meanwhile, Brennan makes plans to spend Christmas in El Salvador, but her father convinces her to spend the holidays with him and Margaret Whitesell, a newly discovered distant relative.

The Jeffersonian team are essentially kidnapped when a mysterious Mr White arrives with a set of remains. The team is told they need to discover the cause of death, but their findings lead the team to suspect they are investigating one of the most famous presidential assassinations in history.