Hufflepuff Holidays

It was a few days until Christmas break started and the halls of Hogwarts were festively decorated and excitement for the upcoming holidays had spread like an invasion of Cornish pixies amongst both students and staff.
In the Grand Staircase the portraits were chatting amiably amongst each other and the castle's ghosts chuckled at the merriment of it all.
Yet in a lone corridor on the fifth floor, one ghost lingered in silence. The ghost waited and waited for over a century, but its companion did not return and too afraid to ask, the ghost refrained from seeking aid.
That is, until three Hufflepuffs came along and decided to help out.