Percy must deliver Santa's Christmas letters to Vicarstown urgently, but a sack of letters is left behind at Dryaw. Harold tries to take them to Percy, but the little engine only thinks he is only mocking his speed. After a snow heap blocks off a tunnel, Harold takes the mail to Vicarstown instead, but ends up getting stuck onthe Mainlandafterwards. Percy later finds him and decides to repay Harold for his good deed.

Thomas is put on quarry duty and there is little passenger traffic on the Harwick Branch Line, so Daisy takes his passengers. Daisy only belittles Annie and Clarabel as she passes by their shed. One day, she has to use them and the coaches get their own back, though their plan does not work as intended.