 Miss Twiddle, a pompous tutor, and her brainy niece Lena came to stay permanently with the Katzenjammers in early 1936.Later in the year Twiddle's ex-pupil, "boy prodigy" Rollo Rhubarb joined them.The ever-smug Rollo is always trying to outwit Hans and Fritz, but his cunning plans often backfire.