It had been second year since Taeyeon worked as a nurse at the Victoria Hospital.
One day, she needed to stay night at the hospital as she had an on-call on that day.

She had been hearing to the hospital staffs that every 13^th December, the hospital will have an earthquake. But it only happens at the hospital only. The rumors said that on 13^th December, there were numerous numbers of people died in a huge earthquake near to the hospital. And this earthquake on 13^th December at the hospital is a reunion of the un-peace souls and spirits.

And somehow, Taeyeon ended being an on-call officer on that date.