The Winston Churchill phrase about Belfast's "murky underworld" comes to mind when assessing the public house shootings in Belfast on Wednesday night. Before to the Loyalist Volunteer Force's admission of responsibility, prominent political and security figures were hinting that members of mainstream paramilitary organisations were involved. If they did not pull the trigger themselves, then they might have provided back-up.
The shooting of Billy Wright, particularly under such controversial circumstances, was bound to be avenged, not once but several times. The expectation at time of writing last night was that more killing was on the way.
As yet there is no sign of a backlash from mainstream republicans, although action by one of the smaller groups, such as the INLA, can never be ruled out. A breakdown in the IRA ceasefire would bring the political edifice that Messrs Adams and McGuinness have built tumbling down.
Such a breakdown would solve short-term political problems for some unionists and loyalists but there is no indication that the Provisional republican movement intends to be so obliging. There is still a lot to play for in the peace process from a republican point of view, and there are hints lately of a significant political development in the US which will strengthen the pan-nationalist consensus.
The chemistry between the Provisional movement and the governments in London and Dublin is said to be good these days. The ball is at Mr Tony Blair's feet and the next few weeks will show whether he can cajole the unionists into a more enthusiastic engagement in the Stormont talks.
Some PhD student ought to write a thesis on "The Role of Prisons in Northern Ireland Politics". There can hardly be another trouble-spot where issues connected with prisoners, their rights and conditions of incarceration have such telling political impact.
The actions taken by the Northern Secretary, Dr Mo Mowlam, on the prisons issue may not have been enough to placate the Ulster Unionist Party, but she must be well aware that too heavy a hand in dealing with prisoners could lead to disaster.
Political wisdom would seem to dictate that she make some significant concessions to loyalist prisoners. However, the last time she tried to do that, by transferring a young killer from Scotland to Northern Ireland, it blew up in her face. It also proved embarrassing for loyalist politicians.
There are rumours that discipline within mainstream loyalist paramilitary circles is under strain and the alleged connection with the New Year's Eve shootings lends some credence to those stories.
It will be an alarming development if the Progressive Unionist Party, political wing of the Ulster Volunteer Force, fails to turn up for the Stormont talks on January 12th. However, talks insiders remain confident they will be there on the day, albeit in a grumbling or, in local parlance, "gurning" mode.
The area where Wednesday night's shooting took place is strongly republican, which makes the action all the more provocative. Small wonder that, by teatime yesterday, three Sinn Fein statements had been issued about the incident in the names of Gerry Adams, Gerry Kelly and Mitchel McLaughlin.
There are worrying reports of more retaliation, possibly in the north Antrim area. One town is said to have "four madmen" who are capable of anything, and there are others elsewhere who, though not capable of a sustained campaign, could nevertheless cause considerable damage.
These rogue acts of violence would be less destabilising if the talks process was in a better state. The dismal failure to reach agreement on the key issues in time for Christmas was not likely to engender hope among the population as a whole. The train we heard so much about in recent months is standing at the station with little sign of forward movement. Meanwhile the killing goes on.