Why? Because you should.
Isis is an Egyptian god. (not the terrorist)
She loved Osiris and got married. (Happy ending right? No)
The gave birth to a son. (Very Lively, his name was Horus)
But then, Osiris was cast into the underworld and was made god of the underworld (Oh no!)
Isis was sad, then she got some crazy idea to marry her son (wait what?)
She then decided to fall in love with someone else (Horus was mad)
So Horus killed the guy (what? No wonder the guy is the god of war)
So then Isis fell in love with another guy and Horus gave up (This is sad)
Meanwhile, Osiris sat in the underworld, thinking of his wife (the end)