The public should be 'clued in' to what's happening. [=should be told about what's happening]
He doesn't have a 'clue' when it comes to fixing cars. [=he knows nothing about fixing cars]
He's totally 'clued in on' [=he knows a lot about] the latest computer developments.
(..) What? Well, it's right here. Read it down. Sigurbj'rn 'sgeirsson. Oh. Uh... Sigurbj'rn 'sgeirsson, that's... That's a clue. Maybe that's a place. It could be a thing. - What are you doing? - I am Googling at feet. - Are you supposed to be doing that? - Welcome to the st century. (..)2008 Journey to the Center of the Earth