Stardate 20011115.1931 (On Screen): The story of how the missionaries were freed is now becoming clear, and no, the Taliban didn't graciously let them go. They were moved out of Kabul and imprisoned in Ghazni, and while they were there, the town was taken by the Northern Alliance, who freed them. (Ghazni is about a quarter of the way along the road that runs from Kabul to Kandahar.) Evidently word was communicated somehow (phone?) to western authorities elsewhere, and they went to a field and were met there by US Special Forces Helicopters (who homed in on a fire that the missionaries set). I suspect the reason that three helicopters went in was simply that it was a dangerous area and they wanted to make sure they had enough force in case it turned out to be a trap. That sounds completely prudent.
It's hard to imagine what an emotional roller coaster those people were on. When they heard fighting outside, and then the door to their cell was broken open by a ragged man holding an assault rifle, and the adrenaline spiked as they were certain they would be shot -- and then he said "Free! Free!" and it turned out he was Northern Alliance and was turning them loose. To go from certainty of death to realization that you're safe in two seconds like that... (discuss)
Update 20011116: Who says irony is dead? It seems that they made their signal fire by burning the burqas the women had been forced to wear by the taliban. That's a gesture which approaches the poetic.