[SPOILERS AHEAD] Detective Yang Se Hyung began investigating the suspects. Park Ji Yoon played the role of a wealthy diver, A Pink's Eunji as a lottery mania who recently lost her grandmother, and Sojin as a tourism development promoter with a son in medical school. The members discovered a metal detector inside Jang Jin's room and a suspicious looking bag on site.
From the first briefing, it was revealed that Hong Jin Ho liked Eunji, Sojin was interested in Jang Jin, and Jang Jin had his eyes locked on Park Ji Yoon, causing much frenzy.
While the investigation went on, they found medical records stating that Eunji's grandmother had died after eating foreign food, which Hong Jin Ho brought to the island. However, Hong Jin Ho denied the reports, saying he had no intention of murder. Despite his cries, Eunji and the rest of the team deemed him as the culprit.
On the other hand, Sojin found one of the victim's shoes by Jang Jin's motorboat and a skeleton arm belonging to Park Ji Yoon's deceased husband. Furthermore, such motives were revealed with Park Ji Yoon claiming she was robbed by the victim, and Sojin saying her son had committed suicide because of the victim. Eunji argued the victim had stolen her lottery ticket. The members agreed, saying, they all "had a legitimate reason to kill."
At last, the results showed Sojin as the person with the most votes. With that, the members failed to solve the case, as Park Ji Yoon had been the criminal all along.