  For certain classes of space(time)s embeddable in a higher dimensional flat
space(time), it appears possible to compute the minimally coupled massless
scalar Green's function in the former by convolving its cousin in the latter
with an appropriate scalar charge density. The physical interpretation is that
beings residing in the higher dimensional flat space(time) may set up sources
to fool the observer confined on the lower dimensional curved submanifold that
she is detecting the field generated by a space(time) point source in her own
world. In this paper we extend the general formula to include a non-zero mass.
We then employ it to derive the Green's function of the massive wave operator
in (d >= 2)-dimensional de Sitter spacetime and that of the Helmholtz
differential operator -- the Laplacian plus a "mass term" -- on the (d >=
2)-sphere. For both cases, the trajectories of the scalar sources are the same
as that of the massless case, while the required scalar charge densities are
determined by solving an eigenvalue equation. To source these massive Green's
functions, we show that the (d+1)-dimensional Minkowski/Euclidean
experimentalists may choose to use either massive or massless scalar line
charges. In de Sitter spacetime, the embedding method employed here leads
directly to a manifest separation between the null cone versus tail terms of
the Green's functions.
