  A crucial step in the operation of the Szilard engine is the isothermal
expansion of a single particle system. This expansion, seemingly a natural
consequence, is unable to proceed when the piston is considered appropriately
to be a thermal system subject to fluctuations in energy at a constant
temperature. The Szilard engine is thus unable to complete its cycle and the
effort to locate the mysterious missing entropy of turns out to be superfluous.
