Season four begins all the way in England, with Booth speaking at Scotland Yard and Brennan guest-lecturing at the prestigious Oxford University. Knowing of Booth and Brennan's expertise in their respective fields, local officials ask for their help with a high-profile murder investigation that involves a British heiress.

In the season finale, a dead body is found at a club called "The Lab." The team has to do some unexpected and unusual things that have to do with this club. Brennan and Booth may become a couple.