Tuesday's brutal shooting of a young man in an Ardoyne alleyway is reminiscent of the worst days of the Troubles.
It provides a severe political test for Matt Baggott, the Chief Constable, not to mention Secretary of State Theresa Villiers and the relationship between Sinn Féin and the DUP.
Mr Baggott, brought in to introduce community policing, is in the eye of the storm and he must speak clearly to the politicians.
Either Sean Kelly is credibly believed to have been responsible for a paramilitary-style attack, or he is not. If he is, Mr Baggott should say so and leave Ms Villiers to decide whether Kelly goes back to jail.
If Kelly is innocent, Mr Baggott should also make this clear and end the political tension that is building up on both sides of the border. Since late summer the DUP has been skittish and uncomfortable in its relationship with Sinn Féin.
Mr Robinson and Mr McGuinness were unable to muster a common front during the flag protests and have only recently started appearing in public together again.
The First Minister has said that Kelly's arrest could have "grave consequences" for the political process.
In response, Mr McGuinness said "the assertion that this shooting in north Belfast, which I unreservedly condemn and the facts of which are at this stage under PSNI investigation and are unclear, should threaten the political process is, frankly, ridiculous. The DUP should keep their nerve".
That is strong language and this is a high-risk game, which is all the more dangerous if it is played in the dark.
Mr Baggott, as the Executive's chief security adviser, needs to speak and end the mystery.
In the Republic Fianna Fáil, resurgent in the polls, senses Sinn Féin could be vulnerable. Niall Collins, its justice spokesman, has called on Sinn Féin leader Gerry Adams to make a statement.
"It is critically important that the facts surrounding this shooting be established immediately and that Sinn Féin move quickly to address questions about the possible involvement of their members," he said.
First we need clear and decisive words from the police. This cannot be allowed to drift into crisis.