Apart from all of the impossible, there is a truth left, no matter how impossible it looks. The following is the original text I found in "Sherlock Holmes": when all other contingencies fail, whatever remains , however improbable, must be the truth.

THE ADVENTURE OF THE BRUCE-PARTINGTON PLANwhen you have eliminated the impossible, whatever remains, however improbable, must be the truth?

THE SIGN OF FOURwhen you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth.

THE ADVENTURE OF THE BLANCHED SOLDIERwhen you have excluded the impossible, whatever remains, however improbable, must be the truth.

THE ADVENTURE OF THE BERYL CORONET