Iran mistakes a British airliner for a U.S. spy plane and shoots it down, and the feisty British PM sees red. Bartlet's initial response would have been more cautious, but he was asleep when the crisis broke, and C.J. was under Abbey's orders not to awaken him. Meanwhile, Toby and a constitutional-law expert (Christopher Lloyd) must explain the U.S. constitution's peculiarities to a delegation from Belarus that asks for help in writing its own founding document.