From Longman Dictionary of Contemporary Englisha sting in the taila sting in the tailSURPRISEDif a story, event, or announcement has a sting in its tail, there is an unpleasant part at the end of it → sting
Examples from the Corpus
a sting in the tail• My stories from Lesbos seemed to carry a sting in the tail for both cultures.• An omelette of rumour, speculation and downright lies, with many a sting in the tail.• But there's a sting in the tail.• And there was a sting in the tail, he warned finally. 