The attackers were relying on the 'element of surprise'. [=they were relying on their attack being a surprise]
I tried living in the city, but I was/felt 'out of my element' there. [=living in the city did not suit me]
At school she was (really) 'in her element'. [=in a place where she was comortable and did well]
(..) Carjacking. resisting arrest... assault with a deadly weapon. You girls fell in with a bad element. I hope you've learned from it. I'm going to turn you over to the care of your parents. They, better than I, (..)1996 Foxfire