Context :

Aims : We aim to perform the first long-term analysis of the system HS Hya .

Methods : We performed an analysis of the long-term evolution of the light curves of the detached eclipsing system HS Hya .
Collecting all available photometric data since its discovery , the light curves were analyzed with a special focus on the evolution of system ’ s inclination .

Results : We find that the system undergoes a rapid change of inclination .
Since its discovery until today the system ’ s inclination changed by more than 15 ^ { \circ } .
The shape of the light curve changes , and now the eclipses are almost undetectable .
The third distant component of the system is causing the precession of the close orbit , and the nodal period is about 631 yr .

Conclusions : New precise observations are desperately needed , preferably this year , because the amplitude of variations is decreasing rapidly every year .
We know only 10 such systems on the whole sky at present .