The Orange marching season starts at Easter and builds to a climax in early July. For the last four years it has produced serious confrontations at Drumcree near Portadown, Co Armagh.
Although last year's protest at the decision of the authorities to ban the march petered out after three young boys were killed in a loyalist petrol-bomb attack, the Portadown Orange lodge appears determined to get through this year. Sporadic protests have continued and Catholic- Protestant relations in the area have reached levels of bitterness unusual even by Northern Ireland standards.
Efforts to defuse the tension received a severe setback with this month's assassination of Rosemary Nelson (above), the local Catholic solicitor killed by a loyalist car bomb.
The Orange Order cannot be confident of the same widespread support as last year if it mounts protests again this year, but the depth of local feeling is such that Drumcree is almost certain to become a flashpoint yet again.
A major political test is also looming in the European elections in June. The Rev Ian Paisley, leader of the Democratic Unionists, traditionally tops the poll in these, with John Hume, of the SDLP, second and a representative of the Ulster Unionists taking the third seat.
The Ulster Unionist leader David Trimble (above) has a two-fold problem. Mr Paisley (below) is intent on turning the contest into a second referendum on the Good Friday Agreement while the Ulster Unionist candidate, Jim Nicholson, could be weakened by his recent admission of an extra-marital affair. If the tide of Unionist opinion flows against the Agreement, and if the conservative electorate punishes Mr Nicholson, Mr Paisley could surge ahead.
Later in the summer, the former Hong Kong governor Chris Patten is due to deliver a far-reaching report on the future of policing in Northern Ireland. Whatever the report contains it will become the focus of a fierce debate, with Unionists attempting to protect the Royal Ulster Constabulary while nationalists seek fundamental changes.
The policing issue, always a sensitive one, has been made thornier still by the death of Mrs Nelson and the revelation that RUC officers appeared to be dismissive and obstructive during an earlier investigation of her complaints that she had been threatened by police.
In sum this timetable suggests that whether or not a breakthrough is made this week the summer will once again be a potentially combustible season in Northern Ireland.