  The $Planck$ satellite has recently completed an all-sky galaxy cluster
survey exploiting the thermal Sunyaev-Zel'dovich (SZ) effect to locate some of
the most massive systems observable. With a median redshift of
$\left<z\right>=0.22$, the clusters found by $Planck$ at $z>0.3$ are proving to
be exceptionally massive and/or disturbed systems. One notable $Planck$
discovery at $z=0.645$, PLCK G147.3-16.6, has a dual core and hosts a radio
halo, indicating it is likely in the process of merging. We present a 16."5
resolution SZ observation of this high-$z$ merger using the Goddard-IRAM
Superconducting 2 Millimeter Observer (GISMO), and compare it to X-ray
follow-up observations with XMM-$Newton$. We find the SZ pressure substructure
is offset from the core components seen in X-ray. We interpret this offset as
possible line of sight temperature or density substructure due to the on-going
merger.
