Jesus has taken His disciples from the Upper Room, scene of the "last supper," up to Gethsemane, just hours before His arrest where He's fingered by the traitor, Judas. There He preps them for "the hinge of history” -- His crucifixion and resurrection. He says after His ascension to heaven, He'll return to earth as King of kings, in great power. No one, not even He, knows when He'll return; only God the Father knows.