The Draco nebula is a high latitude molecular cloud which is supposed
 to interact with HI high velocity clouds (HVCs). HI 21cm line observa-
 tions suggest that the edge of the Draco nebula towards low galactic
 latitudes and longitudes is representing a low velocity shock front
 due to the collisional interaction between the HVCs and galactic disk
 gas. The unusual high CO abundance compared to neutral hydrogen found
 at this edge and the enhanced soft X-ray background emission found in
 the region of the Draco nebula also fit into this picture. However a
 final confirmation of this interaction scenario fails up to now.
 We propose to use PHT to observe the emission of the dust in order
 to look for variations of the dust temperature and composition across
 this filament. In addition we want to observe with the LWS the fine-
 structure lines of CII (158 um), OI (63 um) and NII (122 um) across
 the same feature. These lines will give information about the
 heating/cooling balance of this filament and on the density and tempe-
 rature variations.
 Moreover, we want to look for small, very small grains and especially
 PAHs in the Draco nebula, using the short wavelength bands of PHT.
 Since the Draco nebula has dust counterparts in all four IRAS bands,
 this nebula is a prominent candidate for the detection of PAHs in a
 galactic cirrus cloud and as well for studying the influence of a
 shock wave on these very small particles.