Gardner prepared each of his columns in a painstaking and scholarly fashion and conducted copious correspondence to be sure that everything was fact-checked for mathematical accuracy. But this grapevine, with Gardner at the center, was also a rich source of ideas, mathematical and otherwise, with gossip flowing in many directions. Communications was often by postcard or telephone and Gardner kept meticulous notes of everything, typically on index cards. Archives of just some of his correspondence stored at Stanford University occupy some 63 linear feet of shelf space. This correspondence led to columns about the rep-tiles and pentominos of Solomon W. Golomb; the space filling curves of Bill Gosper; the aperiodic tiles of Roger Penrose; the Game of Life invented by John H. Conway; the superellipse and the Soma cube of Piet Hein; the trapdoor functions of Diffie, Hellman, and Merkle; the flexagons of Stone, Tuckerman, Feynman, and Tukey; the geometrical delights in a book by H. S. M. Coxeter; the game of Hex invented by John Nash; Tutte's account of squaring the square; and many other topics.