  We report the detection of absorption features in the 6-8 micron region
superimposed on a featureless mid-infrared continuum in NGC 4418. For several
of these features this is the first detection in an external galaxy. We compare
the absorption spectrum of NGC 4418 to that of embedded massive protostars and
the Galactic centre, and attribute the absorption features to ice grains and to
hydrogenated amorphous carbon grains. From the depth of the ice features, the
powerful central source responsible for the mid-infrared emission must be
deeply enshrouded. Since this emission is warm and originates in a compact
region, an AGN must be hiding in the nucleus of NGC 4418.
