  V838 Mon erupted at the beginning of 2002. Among various scenarios proposed
to explain the nature of the outburst, the most promising is a stellar merger
event. The results of spectroscopic observations of the object obtained in
October 2005 with the Keck/HIRES instrument, presented in detail in Paper I,
are analysed and discussed. Our analysis of the molecular bands and the P-Cyg
profiles of atomic lines shows that the object loses matter with a velocity of
up to 215 km/s and a rate of 10^{-6} - 10^{-5} M_sun/yr. In the profiles of
some atomic lines, we have also found evidence of matter infall. A narrow
absorption component, which is particularly strong in some P-Cyg profiles, may
indicate that a jet-like outflow has also been formed. We show that the
observed emission in the [Fe II] lines and an eclipse-like event observed in
November/December 2006 was probably caused by interactions of the expanding
matter, ejected by V838 Mon in 2002, with radiation from the B3V companion. In
particular, the observed profiles of the [Fe II] lines can be easily modelled
in this scenario and allow us to estimate parameters of the system, such as the
position of the B3V companion relative to V838 Mon and the line of sight,
density in the outflowing matter, and mass lost in the 2002 eruption. The
observed appearance of strong H-alpha emission, just before and during the
eclipse-like event, can be interpreted as a result of the accretion of the
outflowing matter onto the B3V companion: the accreted matter, shocked above
the stellar surface, can be a source of extreme-UV and soft X-ray radiation
capable of ionizing and exciting H in the outflow.
