  We have identified a new intermediate polar, HS 0943+1404, as part of our
ongoing search for cataclysmic variables in the Hamburg Quasar Survey. The
orbital and white dwarf spin periods determined from time-resolved photometry
and spectroscopy are Porb ~= 250 min and Pspin = 69.171 +- 0.001 min,
respectively. The combination of a large ratio Pspin/Porb ~= 0.3 and a long
orbital period is very unusual compared to the other known intermediate polars.
The magnetic moment of the white dwarf is estimated to be mu1 ~ 10^{34} G cm^3,
which is in the typical range of polars. Our extensive photometry shows that HS
0943+1404 enters into deep (~ 3 mag) low states, which are also a
characteristic feature of polars. We therefore suggest that the system is a
true ``intermediate'' polar that will eventually synchronise, that is, a
transitional object between intermediate polars and polars. The optical
spectrum of HS 0943+1404 also exhibits a number of unusual emission lines, most
noticeably NII 5680, which is likely to reflect enhanced nitrogen abundances in
the envelope of the secondary.
