Baby Jake arrives for a snowy adventure and knock knocks on an igloo door - Pengy Quin opens the door. Hello! Then Baby Jake crawls inside the igloo and shuts the door. Pengy Quin knocks on the door - Baby Jake opens the door. Hello! The friends embark on a knock knock adventure, playing knock knock on Mousey in the Housey's front door and eventually playing knock knock on the big plug and heading underwater for more knock knock fun that culminates in playing knock knock on the big door of an underwater coral palace - the home of friendly Blue Whale.