  We consider a variation of a cops and robbers game in which the cop---here
referred to as "hunter"---is not constrained by the graph but must play in the
dark against a "mole." We characterize the graphs---which we will call
"hunter-win"---on which the hunter can guarantee capture of the mole in bounded
time. We also define an optimal hunter strategy (and consequently an upper
bound on maximum game time on hunter-win graphs) and note that an optimal
hunter strategy need not take advantage of the hunter's unconstrained movement!
This game comes from a puzzle of unknown origin which was told to the authors
by Dick Hess.
