Mission Bin Laden
On a moonless night on Sunday 1 May, four American military helicopters descended on a fortified compound in the quiet town of Abbottabad in north-west Pakistan.
Their mission to capture and if need be, kill, United States Enemy Number One - Osama Bin Laden.
They succeeded and America's most exasperating manhunt was over.
But how did the risky operation unfold both in Washington and in Pakistan?
Rob Walker reports for Assignment.