After days of radio silence, Sum finally hears back from Yun-o. When Sum tries to meet another app connection, things quickly turn violent.

Sum and Yun-o take their relationship to the next level. Meanwhile, Gi-eun goes to the CEO of Spectrum to ask for access to her personal chat history.

Mok-won and Gi-eun need to blow off some steam, so they take Sum along to a night club. Later, Mok-won tries to get Sum to face the truth about Yun-o.

With the walls closing in and threats escalating, Yun-o begins receiving deeply disturbing video chat requests on Somebody.