  We show that consistent nonlinear Partially Massless models cannot be
obtained starting from "f-g" massive gravity, with "f" the embedding de Sitter
space. The obstruction, which is also the source of f-g acausality, is the very
same fifth constraint that removes the notorious sixth ghost excitation. Here,
however, it blocks extension of the mass to cosmological background tuned gauge
invariance that took away the helicity zero mode at linear level. Separately,
our methods allow us to almost complete the class of acausal f-g models.
