  A generalization to the theory of massive gravity is presented which includes
three dynamical metrics. It is shown that at the linear level, the theory
predicts a massless spin-2 field which is decoupled from the other two
gravitons which are massive and interacting. In this regime the matter
naturally should be coupled to massless graviton which introduces a preferred
metric that is the average of the primary metrics. The cosmological solution of
the theory shows the de-Sitter behavior with a function of mass as its
cosmological constant. Surprisingly, it lacks any non-trivial solution when one
of the metrics is taken to be Minkowskian and seems to enhance the predictions
which suggests that there is no homogeneous, isotropic and flat solution for
the standard massive cosmology.
