https://factburger.com/filmburger/movie/the-strange-case-of-the-end-of-civilization-as-we-know-it-1977
The Strange Case of The End of Civilization as We Know It – The grandchild of Professor James Moriarty had promised the world that it has only five days left to live. Moriarty is a master of disguise, a crack shot, and is very patient. Several government figures are shot to death, and it seems that it truly is the end of civilization as we know it - until the President learns that the grandson of Sherlock Holmes is living at 221B Baker Street, and sends the Police Commissioner of Scotland Yard to employ him.