  We provide systematic analysis on a non-Hermitian PT -symmetric quantum
impurity system both in and out of equilibrium, based on exact computations. In
order to understand the interplay between non-Hermiticity and Kondo physics, we
focus on a prototypical noninteracting impurity system, the resonant level
model, with complex coupling constants. Explicitly constructing biorthogonal
basis, we study its thermodynamic properties as well as the Loschmidt echo
starting from the initially disconnected two free fermion chains. Remarkably,
we observe the universal crossover physics in the Loschmidt echo, both in the
PT broken and unbroken regimes. We also find that the ground state quantities
we compute in the PT broken regime can be obtained by analytic continuation. It
turns out that Kondo screening ceases to exist in the PT broken regime, which
was also previously predicted in the non-hermitian Kondo model. All the
analytical results are corroborated against biorthogonal free fermion numerics.
