“Dead. My mother drank a vitamin beverage from a stranger, but it had cyanide in it.”

Sun-kyung meets a strange man, Young-hwan at the secondhand trade for the vacuum cleaner.

Fortunately, Sun-kyung was able to avoid him with the help of her college colleague, Ui-jin.

On the next day, Sun-kyung hears strange words from Detective Cha.

​

“Ui-jin committed suicide after drinking a vitamin drink containing cyanide."

Sun-kyung tells Detective about Yeong-hwan, but Yeong-hwan had an alibi on the day of the incident, as a result of the on-site inspection, it is said that there is no sign of murder.

Sun-kyung, who is gripped by a creepy atmosphere, has a strange conviction.

‘He is the culprit, but why can’t the detectives catch him?'

After that day, Sun-kyung begins to hover around Yeong-hwan.