With a whirr and a grin, Karlson files in!rnOn the ordinary roof of an ordinary house lives an extraordinary man: Karlson! He's the world's greatest at EVERYTHING (he says). Best of all, he has a propeller on his back and can fly! Soon Karlson and Smidge (who lives inside the house) are firm friends.rnBut somebody has spotted Karlson mid-air and now the newspaper is offering a reward for his ca…