leave no stone unturned

present singular third person leaves no stone unturned · participle present leaving no stone unturned · participle past left no stone unturned · past left no stone unturned

1. idiomaticTo search or investigate thoroughly.

   We have a lead inspector who has a global overview of the investigation and will have site handback in mind, although we won't leave any stone unturned.

   2021 December 29, Paul Stephen, “Rail's accident investigators”, in RAIL, number 947, page 30

   1 more example

   “This case of police torture and murder is shocking. But this is not the first case and it is unlikely to be the last case until and unless the police conduct serious interrogations and investigations and leave no stones unturned,” said Sunai Phasuk, a senior researcher for Human Rights Watch.

   2021 August 25, Tassanee Vejpongsa, “Video sparks arrest of Thai police in drug suspect's death”, in The Washington Post, retrieved 26 Aug 2021

2. figurativelyTo perform a task carefully and thoroughly, not missing any step.

   We mean to leave no stone unturned to carry out our intent.

   1897, Bram Stoker, Dracula, published 1993, page 297

   3 more examples

   [He] left unturned no stone / To make my guilt appear, and hide his own.

   1697, Virgil, “The Second Book of the Æneis”, in John Dryden, transl., The Works of Virgil: Containing His Pastorals, Georgics, and Æneis. […], London: […] Jacob Tonson, […], →OCLC

   But we must make it clear that in building our friendship with the Chinese on the mainland we will not sacrifice our Chinese friends on Taiwan. Julian Amery put the issue eloquently: "It is often necessary and legitimate to abandon causes long supported and to dissolve pledged bonds of alliance. But it is always wrong to abandon men who have been friends to their fate. We may have to jettison their interests but we should leave no stone unturned to save at least their lives."

   1988, Richard Nixon, “The Awakened Giant”, in 1999: Victory Without War, Simon and Schuster, →ISBN, →LCCN, →OCLC, page 258

   James Sutherland insists Australia had "no alternative" but to cancel the tour. "We have left no stone unturned in trying to ensure the tour could proceed as planned but at the end of the day the safety and security of our employees must come first."

   2008 March 11, “Australia cancel tour of Pakistan”, in The Guardian, retrieved 02 May 2013