The restaurant is trying to attract more customers, and the new menu is an important 'piece of the puzzle'. [=an important part of what is being done]
Ecologists no longer view different species as independent, but instead see them as pieces of the same 'jigsaw puzzle'.
His strange behavior is a 'puzzle' to his friends. [=his friends don't understand the reason for his strange behavior]
(..) We need to talk to Jennifer. She knows. So tomorrow came. You need to tell her. No. You should. You're the puzzle-maker. We couldn't kill you. We couldn't do anything to change your timeline unless we did something... but nothing. (..)2016 TvShow: 12 Monkeys Title: Lullaby Season: 2 Episode 8
(..) to bring you back from the hotel and bring you to like I did... will do... for you? Plus, you're gonna need another primary. So, me, Jones... we're pieces of the puzzle. You got to make them fit. Okay... so now tell me... what do you need to do to get out of the loop de loop? (..)2016 TvShow: 12 Monkeys Title: Lullaby Season: 2 Episode 8