  The spatiotemporal evolution of the out-of-time-order correlator (OTOC)
measures the propagation and scrambling of local quantum information. For the
transverse field Ising model with open boundaries, the local operator
$\sigma^{x}$ shows an interesting picture of the ground state OTOC where the
local information gets scrambled throughout the entire system and, more
strikingly, starts `unscrambling' upon reflection at the other end. Earlier
discussions of OTOCs did not explain the physical processes responsible for
such scrambling and unscrambling of information. We explicitly show that in the
paramagnetic phase, the scrambling and unscrambling is due to the scattering of
a pair of low-energy spin-flip excitations, even in the presence of small
interactions. In the ferromagnetic phase the same phenomena are explained by
the motion of a domain-wall excitation. Thus, in different limits of the system
parameters, we have provided a simple and almost complete understanding of the
space-time pictures of the OTOCs, including the unscrambling, in terms of the
low-energy excitations like one and two spin-flips or a single domain wall.
