Professor Indiana Jones is about to lecture the Pennsylvania History Society when some trouble with his microphone stand leads him off into recounting a disastrous spy mission in which he was involved in May 1917. Jones had joined up with an international trio of spies plotting against their German counterparts in the neutral city of Barcelona. After his old acquaintance Pablo Picasso helped him get a job at Sergei Diaghilev's Ballets Russes, Indy devised a plan to forge a love letter written by the German cultural attaché to make it seem the man was having an affair with the Countess of Toledo.