  We present the first example of a unitary theory of Lorentz-invariant massive
gravity, with all degrees of freedom propagating on a strictly homogeneous and
isotropic, self-accelerating de Sitter background. The theory is a simple
extension of the quasidilaton theory, respecting the symmetry of the original
theory but allowing for a new type of coupling between the massive graviton and
the quasidilaton scalar.
