S2, E9: Poirot is called in at the highest level when the British Prime Minister is kidnapped in France en route to a disarmament conference. The kidnap was preceded by a gun attack on the PM as he travelled on the boat train after seeing the King at Windsor. With only 32 hours to go before the conference is due to start, Poirot confounds the government by refusing to cross the channel. He pursues his investigation in England.