  Here we present the `soldering' of opposite helicity states of a spin-3
particle, in $D=2+1$, into one parity doublet. The starting points may be
either the sixth- or the fifth-order (in derivatives) spin-3 self-dual models
of opposite helicities. The high number of derivatives avoids the use of
auxiliary fields which has been so far an obstacle for a successful soldering
procedure. The resulting doublet model is a new Lagrangian with six orders in
derivatives and no auxiliary field. It may be regarded as a spin-3 analogue of
the linearized `New Massive Gravity'. We check its particle content via a gauge
invariant and Lorentz covariant analysis of the analytic structure of the
two-point amplitude with the help of spin-3 analogues of the Barnes and Rivers
projection operators. The particle content is alternatively confirmed in a
specific non-covariant gauge by a decomposition in helicity variables. The
soldered model is ghost free and contains two physical states as expected for a
parity doublet.
