On June 28, 1914, Gavrilo Princip assassinated Archduke Franz Ferdinand of Austria in Sarajevo, setting in motion the events leading to the outbreak of World War I. On July 25, according to later passport, Harris revisited Moscow, possibly taking an opportunity to visit Frederick B. Thomas. Thomas (now using the Russified version of his name, Fyodor Tomas) had become the owner of the Aumont Theater in 1911 and had converted it into Moscow's popular amusement park, the Aquarium Garden Theater. Besides its various entertainment establishments, the park also held private residences, hotels, cafes and cinemas. The latest attraction at the Aquarium was Jack Johnson, America's Heavyweight Champion, who was preparing for a boxing tournament between Johnson and M. P. Tsarev that was initially to be held on July 28. However, the tournament was called off due to the news of chaos coming from other parts of Europe. Harris would have witnessed off-duty army officers spending time at the Aquarium, sipping champagne, staring at the chorus girls, and some of them meeting and dining with Johnson.