Pieces of the puzzle.

Discusses the investigation into the terrorist attacks on the United States, and the efforts of investigators in the U.S. to link Osama bin Laden to the attacks. Actions of U.S. Federal Bureau of Investigation director Robert Mueller; Arrest of people thought to be linked to the attacks; Outlook for the cooperation of suspects; Need for evidence against bin Laden before an attack can be launched by the U.S. against the Al Qaeda organization.