"Ahu" are stone platforms on which many moai sit. There are 313 known ahu and 125 of these carry moai. The biggest, Ahu Tongariki is 220 m (720 ft), and had the most (15) and tallest moai.
The subject matter is very tricky. It's about the Munich massacre and what Mossad did afterwards with the assassination squads. I think it's a turning point in history, especially for the Palestinians.