  V4334 Sgr (Sakurai's object) is an enigmatic evolved star that underwent a
very late thermal pulse a few years before its discovery in 1996. It ejected a
new, hydrogen-deficient nebula in the process. Emission lines from the newly
ejected gas were first discovered in 1998 (He I 1083 nm) and 2001 (optical). We
have monitored the optical emission spectrum since. From 2001 through 2007 the
optical spectrum showed an exponential decline in flux, consistent with a shock
that occurred around 1998 and started cooling soon after that. In this paper we
show that since 2008 the line fluxes have been continuously rising again. Our
preliminary interpretation is that this emission comes from a region close to
the central star, and is excited by a second shock. This shock may have been
induced by an increase in the stellar mass loss and wind velocity associated
with a rise in the stellar temperature.
