  We present a radiative-transfer calculation which reproduces the infrared
spectrum of the planetary nebula BD+30$^{\circ}$3639, fitting both the spectral
energy distribution and the spatial extent at infrared wavelengths. We obtain
an acceptable fit to most of the spectrum, including the infrared bands. The
fit requires a distance of $\ge 2 \kpc$, which implies that BD+30$^\circ$3639
has evolved from a massive progenitor of several solar masses. Two surprising
results are (1) a very low dust-to-gas ratio, (2) an absence of the smallest
PAH molecules. Extrapolating back in time, we calculate the previous infrared
evolution of BD+30$^\circ$3639.
