you are likely to find People in/at/on Opera. you are likely to find Performer in/at/on Opera. 
Danger is related to Need. Need is related to Shadow. Shadow is a type of Dominate. Dominate is the opposite of Submit. 
People --AtLocation--> Opera <--AtLocation-- Performer 
Danger <--RelatedTo--> Need <--RelatedTo--> Shadow --IsA--> Dominate <--Antonym--> Submit 