  We derive an equivalence between the (2,0) superconformal M5-brane field
theory dimensionally reduced on a squashed three-sphere, and Chern-Simons
theory with complex gauge group. In the reduction, the massless fermions obtain
an action which is second order in derivatives and are reinterpreted as ghosts
for gauge fixing the emergent non-compact gauge symmetry. A squashing parameter
in the geometry controls the imaginary part of the complex Chern-Simons level.
