Russia's military commander in Chechnya, Anatoly Kulikov, had sent an order to stop the cavalcade of coaches from moving any further along a previously agreed route. The itinerary, he instructed, had been changed.
The Chechen fighters, on the way home after holding some 1,500 people captive in a southern Russian hospital, suspected a trap. Convinced the government was about to renege on a promise of safe passage, they readied their guns and grenade launchers. The more jittery pleaded with their leader, Shamil Basayev, to pre-empt what seemed like an imminent assault.
Grigory Sanin, a journalist for the Russian newspaper Sevodnya travelling with the Chechens as a volunteer human shield, said: "Everyone expected an immediate attack. The terrorists prepared for battle. What would come next, no one knew - not the fighters, not the hostages."
Nor, it seems, the Kremlin. Also at stake on that lonely country road en route from Budennovsk to Chechnya on Monday night was an explosive power struggle in Moscow: who would prevail, the hard men of Russia's security services, in the ascendant since the start of Russia's war in Chechnya last December, or more moderate voices counselling compromise?
Terrified that the Russian military was about to strike, Yuli Rybakov, a member of parliament riding in the buses, called the office of Prime Minister Viktor Chernomyrdin on a satellite telephone and begged the authorities to halt whatever it was they were planning.
After a botched attempt two days earier to storm the hospital in Budennovsk, Mr Chernomyrdin had intervened. The deal he negotiated with Mr Basayev had freed most of the hostages but, on the road to Mozdok, now risked falling apart in another explosion of bloodshed.
Half an hour after the call, the helicopters vanished, the buses turned around and the Chechens lowered their guns. The next night - after more delays, more nervous negotiation and a long, roundabout journey through Dagestan, the coaches finally made it to rebel-held mountains in the remote south-eastern corner of Chechnya. The last hostages were set free. Mr Basayev and his gunmen vanished into the hills.
Mr Chernomyrdin had prevailed. Humiliated and out-manoeuvred, Russia's "power ministers" - defence, interior and secret service - could barely contain their fury. "Don't make heroes of the rebels. Terrorism is an armed dirty trick," fumed a front-page headline in Wednesday's edition of the military's official organ, Krasnaya Zvezda (Red Star). Mocking Mr Chernomyrdin as a "a kind uncle", it said: "Instead of hitting back, it will soon become good form to turn the other cheek so the culprit can give one more slap."
Russia's Defence Minister, Pavel Grachev, was outraged that the hostage- takers had been allowed to get away. "Basayev's band could have been liquidated either in Budennovsk or at points along the route to Chechnya," he said, all but acknowledging that plans had indeed been drawn up to storm the convoy of buses. "All means, including highly trained specialists, are available."
Gen Kulikov, the Interior Ministry commander who ordered the coaches blocked near Mozdok, also vented his spleen. He threatened to break off a Chechnya ceasefire mandated by Mr Chernomyrdin if rebels did not hand over Mr Basayev immediately. No sooner had he made the threat, though, than Moscow slapped him down for insubordination. "Gen Kulikov does not have the authority to decide to break a moratorium, because military operations were stopped by an order from the Prime Minister," said Viktor Konnov, the government spokesman.
After a six-month-long war in Chechnya that has killed tens of thousands of civilians and more than 1,500 Russian soldiers, reduced much of the region to rubble and sent President Yeltsin's popularity rating nosediving into single figures, the mayhem in Budennovsk has crystallised a significant shift in power politics. "The tragedy and grief of Budennovsk will probably be seen as a reference point of a new political era," said Mr Chernomyrdin on Friday.
What this will bring is uncertain. Parliament is on the rampage, the government faces a confidence vote, and early elections are possible. But, for perhaps the first time since MrYeltsin sent troops into Chechnya on 11 December, the military has, at least temporarily, lost the right to dictate Kremlin decision-making.
After months of public support for his deeply unpopular ministers of defence, interior and security, Mr Yeltsin last week promised heads would roll. In a televised speech he savaged security forces for incompetence.
It could easily all have gone the other way. Sergei Kovalyov, a human- rights activist who volunteered himself as a human shield for the bus journey back to Chechnya, believes the military came within a hair's breadth of attacking the convoy. "It seems that the delay of 24 hours was connected with the development of plans for an assault. How many of us would have died if such an attempt had been made, I do not know."Reuse content