Time-Limited Cycle?

The three of them immediately sprung to their feet and scanned the area around them. Because what if… what if the bus officer was the size of a palm this time? Or perhaps invisible? However, they waited and waited, and no familiar greeting of 'Welcome, everyone. Thank you for boarding the bus in time' as they had already gotten familiar with now.

Instead, silence settled in, accentuating the stillness in the atmosphere. Only the soft ticking of a clock pervaded the air. 

Tick-tick-tick.

It was an ordinary sound, something they could hear in everyday's life. Yet for some reason, the more one focused on it, the more an inexplicable chill seemed to creep down their spine.