  We present Spitzer Space Telescope and complementary ground-based infrared
observations of the recurrent nova RS Ophiuchi, obtained over the period 64-111
days after the 2006 eruption. The Spitzer IRS data show a rich emission line
spectrum superimposed on a free-free continuum. The presence of fine structure
and coronal infrared lines lead us to deduce that there are at least two
temperatures (1.5e5K and 9e5K) in the ejecta/wind environment, and that the
electron density in the `cooler' region is 2.2e5 cm-3. The determination of
elemental abundances is not straightforward but on the assumption that the Ne
and O fine structure lines arise in the same volume of the ejecta, the O/Ne
ratio is >~0.6 by number.
