  Revivals of initial non-equilibrium states is an ever-present concern for the
theory of dynamic thermalization in many-body quantum systems. Here we consider
a nonintegrable lattice of interacting spins 1/2 and show how to construct a
quantum state such that a given spin 1/2 is maximally polarized initially and
then exhibits an almost complete recovery of the initial polarization at a
predetermined moment of time. An experimental observation of such revivals may
be utilized to benchmark quantum simulators with a measurement of only one
local observable. We further propose to utilize these revivals for a delayed
disclosure of a secret.
