At 12.36pm on the day, the Taoiseach of the Irish Republic was warmly applauded in the Central Hall beneath Craigavon's bronzy glare. Even if the local history of his speechwriter was a little ropey. (King George V did not open Stormont. He delivered his conciliatory 1921 speech (drafted by General Smuts) in Belfast City Hall.)

But no matter. At 12.45 an Irish republican heartily applauded a British prime minister. At 1.07 on BBC Radio 4 the president of Sinn Fein paid a tribute, in Irish, to the Paisleyite MLA, the late George Dawson.

Was any of this real? They say the camera cannot lie. The music was sadly banal for a county whose green hills outside the walls claim Hamilton Harty as their own, not to mention the loaded riches of Stanford and Tom Moore in the island at large.

Then they emerged through the pinned-back revolving door of the Parliament Building, the leading players, Taoiseach and Prime Minister, Dublin Foreign Minister and our new deputy First Minister - and the First Minister himself.

All shook hands warmly. Well, not quite all. Paisley was standing between Blair and McGuinness as the Prime Minister stretched across to shake hands with the Deputy First Minister.

Paisley, discomfited, found reason to stare fixedly into the distance to his left.

It was then we realised that the sole, most loaded handshake was still missing.

So were absent friends.

Where was Major? Trimble? Mallon? Why did Hume have to rely on the party coat-tails of the SDLP to get in? This was the DUP-Sinn Fein show.

The way ahead is stony and rough. Three factors will decide the fate of the administration: the nature of the challenge is one; ministers' capacity to meet it is another.

A total of 26 local councils must be pared - only a handful are needed. To make progress, the new ministers will find they have to make enemies. The issue of academic selection splits the administration down the middle. The grammar schools will fight to the death to control their intake.

Householders just now are feeling the hike in the rates; water charges will not go away just because direct rule ministers have, as some simpletons seem to imagine.

In the hospitals, 100 or more patients a week lie on trolleys for more than 12 hours and £1m a month is being wasted on cancelled or missed appointments. New houses are beyond the reach of young couples. Much of our planning is a mess.

Against this our new ministers must prove themselves. Stormont has an uneven administrative record. Craigavon hung on too long between the wars, becoming addicted to winter cruises. His successor, JM Andrews, was not really up to it and could not handle the wartime challenge, allowing meagre civil defence equipment to be sent back to Britain in 1940 in a province devoid of air raid shelters.

The extent of the slaughter in the Blitz months later was a judgment on more than the Luftwaffe.

From 1943, Basil Brooke was personable and energetic, but more soldier than politician and lacked vision, eventually growing lazy in a 20-year premiership and slipping off to fish the Colebrooke on his 1,300 acres in Fermanagh every Thursday afternoon.

The able, obvious successor of liberal instinct, who could have hastened Brookeborough's retirement, Maynard Sinclair, had been lost on the Princess Victoria in 1953.

So he hung on, and when Terence O'Neill succeeded after another decade, the years of the locust had taken their toll.

He knew something had to be done, but, lacking political nous, was unsure how to do it. When he had to go in 1969, James Chichester-Clark was pushed in by the old guard to stop Brian Faulkner, but was soon out of his depth as the situation on the ground slipped towards the pit. When Faulkner did claim the prize in 1971, there was no damming the flood.

Where Paisley and McGuinness fit into this scenario it is too early to say. Much depends upon the third factor: the extent to which their party rank and file have followed them along the Damascus road.

Alone and unsupported on the ground, the new dual regime will not last long.

How the police fare on difficult days will be important. So will the tenor of the marching season.

The economy will play its part. So will Gordon Brown and the possibility of a new Taoiseach.

We are about to live in interesting times.