That it was Duchamp who precipitated the Copernican turn-around in art is an opinion long shared, and not only by insiders. The oeuvre Duchamp left us is exceedingly small, but hardly any of his works did not have to undergo multiple interpretations of an art historic, psychological, socio-critical or alchemist kind. And yet, it is odd: Duchamp's last work "in oil and vinegar", Tu m from 1918, has never drawn extensive attention among his exegetes. Already the title poses a riddle: Does it mean "Tu m'aimes" (you love me) or, as most frequently guessed, "Tu m'embetes" (you bore me), or, more poignantly even, "Tu m'emmerdes" (kiss my ass)? Karl Gerstner, one of the prominent Swiss graphic designers who still knew Duchamp personally, was first taken aback by the work - but also fascinated at the same time. He then proceeded to get a picture of the picture himself in order to satisfy his curiosity. And the more deeply he penetrated into the matter the more his surprise abated and his fascination grew. - Enter this book, encouraged by Richard Hamilton, perhaps the most intimate Duchamp connoisseur, 20 analytical essays solving riddles galore.