BC Gruis is an over-contact system with the components differing by about 9% in temperature and thus displaying uneven eclipse depths. The orbital period has changed since discovery, which may be due to error in the original determination and also possible mass exchange and/or the effects of a third component. A third component in the system, revealed by spectroscopy, has been reported from the ESO and may contribute to variability in the orbital period. An astrophysical model was developed by Plewa & Kaluzny in 1992 before the 3rd component was discovered. A revised model will be presented.