  Minimal observational evidence exists for fast transition region (TR) upflows
in the presence of cool loops. Observations of such occurrences challenge
notions of standard solar atmospheric heating models, as well as their
description of bright TR emission. Using the {\it EUV Imaging Spectrometer}
(EIS) onboard {\it Hinode}, we observe fast upflows ($v_\lambda$\,$\le$\,$-$10
km s$^{-1}$) over multiple TR temperatures (5.8\,$\le$\,$\log T$\,$\le$ 6.0) at
the footpoint sites of a cool loop ($\log T$\,$\le$\,6.0). Prior to cool loop
energizing, asymmetric flows of $+$\,5 km s$^{-1}$ and $-$\,60 km s$^{-1}$ are
observed at footpoint sites. These flows speeds and patterns occur
simultaneously with both magnetic flux cancellation (at site of upflows only)
derived from the {\it Solar Dynamics Observatory}'s (SDOs) { \it Helioseismic
Magnetic Imager}'s (HMI) line-of-sight magnetogram images, and a 30\% mass
in-flux at coronal heights. The incurred non-equilibrium structure of the cool
loop leads to a catastrophic cooling event, with subsequent plasma evaporation
indicating the TR as the heating site. From the magnetic flux evolution we
conclude that magnetic reconnection between the footpoint and background field
are responsible for observed fast TR plasma upflows.
