  Near-infrared, JHKL, photometry of eta Car is reported covering the period
2000 to 2004. This includes the 2003 shell event which was the subject of an
international multi-wavelength campaign. The fading that accompanied this event
was similar to, although slightly deeper than, that which accompanied the
previous one. The period between these events is 2023+/-3 days and they are
strictly periodic. Their cause, as well as that of the quasi-periodic
variations and secular brightening are discussed. It seems possible that all
three types of variability are consequences of the binary nature of the star.
