Kristel found a thick layer of snow on her doorstep.

It looks like she slept well last night and didn’t notice that there was snow.

She swept her gaze to the hallway, where she could hardly see the railings.

She observed her surroundings after she noticed several shoe prints around her door, but the deep prints at her doorstep caught her attention the most, as if someone had been loitering there for a long time.

Last night, someone rang her doorbell. That time the snow hadn’t fallen yet.

When she came to the door, she opened it. No one was there.

So who would stay at her doorstep all night...