  We report high-resolution observations at mid-infrared wavelengths of a minor
solar flare, SOL2014-09-24T17T17:50 (C7.0), using Quantum Well Infrared
Photodetector (QWIP) cameras at an auxiliary of the McMath-Pierce telescope.
The flare emissions, the first simultaneous observations in two mid-infrared
bands at $5\ \mu$m and $8\ \mu$m with white-light and hard X-ray coverage,
revealed impulsive time variability with increases on time scales of $\sim 4$~s
followed by exponential decay at $\sim$10 s in two bright regions separated by
about 13$"$. The brightest source is compact, unresolved spatially at the
diffraction limit ($1.3"$ at $5\ \mu$m). We identify the IR sources as flare
ribbons also seen in white-light emission at 6173~\AA~observed by SDO/HMI, with
twin hard X-ray sources observed by RHESSI, and with EUV sources (e.g., 94~\AA)
observed by SDO/AIA. The two infrared points have closely the same flux density
($f_\nu$, W/m$^2$Hz) and extrapolate to a level about an order of magnitude
below that observed in the visible band by HMI, but with a flux more than two
orders of magnitude above the free-free continuum from the hot ($\sim$15 MK)
coronal flare loop observed in the X-ray range. The observations suggest that
the IR emission is optically thin, this constraint and others suggest major
contributions from a density less than about $3 \times 10^{13}$~cm$^{-3}$. We
tentatively interpret this emission mechanism as predominantly free-free
emission in a highly ionized but cool and rather dense chromospheric region.
