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.
(..) Not only has Special Agent Chester Desmond disappeared... without a trace, but this is one of Cole's blue rose cases. The clues found by Special Agent Desmond and Agent Stanley... have led to dead ends. The letter extracted from beneath the fingernail of Teresa Banks... gives me the feeling (..)1992 Twin Peaks: Fire Walk with Me