Max, Leon and Matthew - together at last for Christmas at St Mary's - a time of conspicuous consumption, riotous misbehaviour and the traditional illegal Christmas jump. And this time, it's inter-generational.
Donning her unfamiliar mother hat, Max takes Matthew back to 19th century London, where they plan to deliver a parcel of Christmas cheer to his former friends, but find themselves confronting the terrifying Old Ma Scrope in the process.
'Tis the season to be jolly.
It's also the season of goodwill towards all mankind.