Marushiro Maruda was inserted with radium for hemorrhoid treatment. He took the opportunity to escape and hid the radium in prison. In prison, he and Igarashi Shokichi made paper balloons together, during which Maruta cleverly hid radium in orange paper balloons. After being released from prison, Maruda searches for orange paper balloons but fails to find the radium, recalling that Igarashi may have stolen the radium. Soon after, Igarashi was found dead in a dilapidated hut with an ulcer under his left ribs. Maruta suspected that it was related to radium, and he regretted killing someone. So, how did Igarashi obtain radium? Where is the radium now?
