The Impossible Crossword Clue: Can You Guess the Opposite of a Heads Up?

As a detective tasked with solving the mystery of the crossword clue ‘Opposite of a heads up?’, my initial thought was to try and determine what the clue meant by ‘heads up’. I know that a ‘heads up’ is an idiom that means a warning or advance notice, so the opposite of that would be something that comes without warning or is unexpected. My mind went immediately to the game of coin-flipping where a player calls ‘heads’ or ‘tails’ before the coin is flipped. If we consider ‘heads’ as the option that is signaled and ‘tails’ as the lack of a signal, then the answer to the crossword clue would have to be ‘TAILS.’ The insight that led me to this answer was understanding the opposite of ‘heads up,’ and then linking it to the common phrase and simple game of coin-flipping. Overall, the process of solving this mystery was challenging and required a combination of linguistic and analytical skills to come up with the correct answer.