  As part of the Red MSX Source Survey of Massive Young Stellar Objects (MYSOs)
we have conducted multi-wavelength follow up observations of the well-known
object V645 Cygni. We present our data on this object, whose near-infrared
spectrum is exceptional and place these in context with previous observations.
Our observations of V645 Cyg included near/mid infrared imaging observations,
13CO 2-1 line observations and high signal-to-noise velocity resolved
near-infrared spectroscopy. The spectrum shows P-Cygni hydrogen Brackett
emission, consistent with a high velocity stellar wind. A red-shifted emission
component to a number of near-IR emission lines was also uncovered. This is
associated with a similar component in the H alpha line. V645 Cyg is also found
to have variable CO first overtone bandhead emission. The data clearly indicate
that the outflow of V645 Cyg is variable. The unidentified feature in a
previously published optical spectrum is identified with a receding outflow at
2000 km per second. The nature of this feature, which is found in hydrogen and
helium atomic lines and CO molecular lines remains a puzzle.
