Leave no stone unturned Neutral

To make every possible effort and try every possible method in order to find or achieve something.

It implies real thoroughness bordering on exhaustiveness, often used to reassure someone that a search or investigation is being taken seriously.

The image comes from ancient Greece, though the most famous version of its origin story is probably more legend than fact. According to a tale recorded centuries later by writers such as the geographer Pausanias, the Theban general Polycrates was searching for treasure supposedly buried by the defeated Persian commander Mardonius after the Battle of Plataea in 479 BC; he consulted the Oracle of Delphi, who advised him to “turn every stone” (panta lithon kinei). However, the classicist Joseph Fontenrose argued that this Polycrates anecdote reads like a fable invented to illustrate a proverb rather than a real historical event, and pointed out that the underlying Greek phrase — “panta kinēsai petron,” to move every stone — already appears in Euripides’ tragedy “The Children of Heracles,” written around 430 BC, which predates the supposed oracle consultation and suggests the proverb existed independently of that specific story. The expression entered English much later on its own terms; the earliest known printed English use, from around 1555, appears in a text warning young gentlemen about the tricks used by dishonest gamblers, showing that by the mid-16th century the phrase had already settled into its modern figurative sense of thoroughness.

The detectives promised the family they would leave no stone unturned until the case was solved.

Our research team left no stone unturned before publishing the final report.

When it comes to finding the right supplier, we leave no stone unturned.

A: Are you sure you checked everywhere for the missing files? B: Absolutely — we left no stone unturned.