An angry President Nixon on October 20, 1973, a Saturday, ordered AG Elliot Richardson to fire Watergate special prosecuter Archibald Cox. Richardson refused and tendered his resignation. The President then ordered DAG William Ruckelshaus to drop the axe on Cox. He refused, and also resigned.
This chain of events left Solicitor General, Robert Bork as acting head of Justice. Thus it is Bork's turn. Nixon submits the order to him. Bork believed that the President was within his rights to place such an order, but not wanting to be perceived as "The President's Man" he also considered resignation. However, Richardson prevailed upon Bork to stay in office, for if not, there would be no one left in Justice who knew how the Department worked.
Hence, "Saturday Night Massacre;" and the rest is history.
"I am not a crook."
Washington Post, October 21, 1973
Modesto Bee, October 22, 1973