  We continue to explore the accretion model of the massive binary system eta
Carinae by studying the anomalously high He II 4686 line. The line appears just
before periastron and disappears immediately thereafter. Based on the He II
4686 line emission from O-stars and their modeling in the literature, we
postulate that the He II 4686 line comes from the acceleration zone of the
secondary stellar wind. We attribute the large increase in the line intensity
to a slight increase in the density of the secondary stellar wind in its
acceleration zone. The increase in density could be due to the ionization and
subsequent deceleration of the wind by the enhanced X-ray emission arising from
the shocked secondary wind further downstream or to accretion of the primary
stellar wind. Accretion around the secondary equatorial plane gives rise to
collimation of the secondary wind, which increases its density, hence enhancing
the He II 4686 emission line. In contrast with previous explanations, the
presently proposed model does not require a prohibitively high X-ray flux to
directly photoionize the He.
