  We discuss a variation of quadratic gravity in which the gravitational
interaction remains weakly coupled at all energies, but is assisted by a
Yang-Mills gauge theory which becomes strong at the Planck scale. The
Yang-Mills interaction is used to induce the usual Einstein-Hilbert term, which
was taken to be small or absent in the original action. We study the spin-two
propagator in detail, with a focus on the high mass resonance which is shifted
off the real axis by the coupling to real decay channels. We calculate
scattering in the $J=2$ partial wave and show explicitly that unitarity is
satisfied. The theory will in general have a large cosmological constant and we
study possible solutions to this, including a unimodular version of the theory.
Overall, the theory satisfies our present tests for being a ultraviolet
completion of quantum gravity.
