Koizumi theorizes that the mountain mansion is an artificially constructed scenario and that they're all clones of their original selves set loose in the mansion like a role-playing simulation to gauge their reactions.; The S.O.S. Brigade find an injured wolf cub sheltered under the front porch and nurse it back to health.; Koizumi invents a role-playing murder mystery for the S.O.S. Brigade to solve and the key to the mystery involves Shamisen.; Through brilliant deductive reasoning, Haruhi and Tsuruya solve the mystery.; While the others focus on nursing Yuki, Koizumi gives Kyon a formula that will either end the sim and return them to reality or end their reality and destroy them all.