Who are the inventors of Tlön? The plural is inevitable, because the hypothesis of a lone inventor - an infinite Leibniz laboring away darkly and modestly - has been unanimously discounted. It is conjectured that this brave new world is the work of a secret society of astronomers, biologists, engineers, metaphysicians, poets, chemists, algebraists, moralists, painters, geometers... directed by an obscure man of genius. Individuals mastering these diverse disciplines are abundant, but not so those capable of inventiveness and less so those capable of subordinating that inventiveness to a rigorous and systematic plan.