 Thomas is sent to fetch a Christmas tree, but runs into a snowdrift.It is up to Donald and Douglas to save the day for him.When Percy has to go to the Works for repairs, Diesel returns to Sodor and, as expected, causes trouble for the engines by destroying the oldest truck in Ffarqhuar Yards, but two days later, Thomas has an accident when Daisy drips her oil on the track and Clarabel's back wheels come off the tracks at the special points at Dryaw, so Diesel comes to the rescue.