Moon Ha-rin is a dawn delivery driver and the sole witness who received a delivery completion notification for a door that does not exist on the 17th floor.
Moon Ha-rin wants to trust Ryu-geon, but remains cautious about what she says until it reaches the management office.
Source stage
More discoveries
Seo Ji-hoo attempts to extract the cache of a sealed group chat to revive the voices of deleted residents.
Seo Ji-hoo, a part-time CCTV inspector, can restore the video gaps where a black resident card was swiped.
Seo Ji-hoo suspects that the Blue Line is not a power line but a deletion line that burns complaint files.
Joo Ah-rin is a transfer student who arrived after her older sister disappeared. She strives not to miss her sister's roll call response from behind the white door.
