No stone unturned.
No stone unturned.
Leaving "no stone unturned" is to be extremely thorough and exhaustive in searching or investigating. It stems from the idea of looking under every rock to find what is hidden beneath. This idiom is frequently used in situations where every possible effort is made to find something or solve a mystery, ensuring that no possible avenue of inquiry is overlooked.
Leave no stone unturned.
Make every possible effort.
To find the missing document, he left no stone unturned.
To find the missing document, he made every effort.
The detectives left no stone unturned in their search for the truth.
The detectives made every effort in their search for the truth.