The Murdoch scandal.
The sky is dark with chickens coming home to roost.
Rebekah Brooks resigns and a day later is arrested. Les Hinton resigns. Further arrests are on the way. The noose grows tighter ever tighter around James Murdoch.
Meanwhile Sir Paul Stephens resigns as the Met Police commissioner- inevitable sooner or later, but interesting that it was sooner.
Some of the more excitable may say that Cameron himself is under threat, but in the political game of mutual assured destruction, he is no more guilty than most, and a lot less guilty than many. Tony Blair has probably not been sleeping too well recently either. In fact, although not good for the PM, it would take a far more dramatic escalation for his position to be under real pressure. Cameron may have made some new enemies, not least Sir Paul Stephens, apparently, but that is the swings and roundabouts of politics.
Meanwhile the Liberal, Democrats came under attack for being the only party with completely clean hands -not just because "Murdoch would not take their call" (thank you, Cristina!), but because the loathing of Murdoch was mutual. I think it takes a certain kind of prejudice to argue that the Lib Dems have behaved badly in this affair. Vince Cable may have shot his mouth off in a moment of vanity, but the Lib Dems have detested the Dirty Digger for decades and despised almost everything he represented with great ferocity.
So what is the real end game?
The scandal will continue to spread.
Murdoch will face ruin.
The Police will be investigated further and more News International and Police resignations and indeed arrests will take place.
On the other hand, while Ed Miliband may have won the first phase, it is not in his interests for much more than that to happen.
After all, if the can of worms of the last Labour government is opened, then the scale of the scandal will indeed enter the stratosphere.