In 1939, the Republic of Barataria had an exhibition at the New York World's Fair. One of the exhibits on display was Prince Rubio.
On September 21, 1939, Prince Rubio bit Lawrence and ran away. A grey sheepdog owned by the Brown family, Einstein, escaped from Emmett Brown's time train. He was mistaken for Prince Rufio, and Lawrence took him to the Barataria exhibition. Lawrence was sick of being treated as nothing but Prince Rufio's handler, and decided to use cold bathwater to make "Prince Rubio" as miserable as he felt.
When Doc Brown used a scanner to track Einstein's location, both dogs escaped, and Lawrence claimed that the Browns had attempted to steal Prince Rufio.
The police were alerted that Prince Rufio was loose, and the Browns were threatened with extradition by the Baratarian embassy. Clara and Emmett Brown ran from from the Baratarian guards, while their sons, Jules and Verne, found the dogs. The boys thought that the two dogs were both Einstein, just different temporal versions due to time travel. After both dogs ran away again, Jules attempted to use his scanner to find out where they went, not knowing that Lawrence had removed the tracking collar from Einstein's neck. When the scanner activated, it was discovered by two German spies, Karl and Fritz , who planned on giving the tracker to Adolf Hitler to aid in his quest to conquer the world.