  Plasma flows within prominences/filaments have been observed for many years
and hold valuable clues concerning the mass and energy balance within these
structures. Previous observations of these flows primarily come from H-alpha
and cool EUV lines (e.g., 304A) where estimates of the size of the prominence
threads has been limited by the resolution of the available instrumentation.
Evidence of `counter-steaming' flows has previously been inferred from these
cool plasma observations but now, for the first time, these flows have been
directly imaged along fundamental filament threads within the million degree
corona (at 193A). In this work we present observations of an active region
filament observed with Hi-C that exhibits anti-parallel flows along adjacent
filament threads. Complementary data from SDO/AIA and HMI are presented. The
ultra-high spatial and temporal resolution of Hi-C allow the anti-parallel flow
velocities to be measured (70-80 km/s) and gives an indication of the
resolvable thickness of the individual strands (0.8'' +/- 0.1''). The
temperature distribution of the plasma flows was estimated to be log T(K) =
5.45 +/- 0.10 using EM loci analysis. We find that SDO/AIA cannot clearly
observe these anti-parallel flows nor measure their velocity or thread width
due to its larger pixel size. We suggest that
  anti-parallel/counter-streaming flows are likely commonplace within all
filaments and are currently not observed in EUV due to current instrument
spatial resolution.

Solar and Stellar Astrophysics