When the swollen Limpopo river burst its banks and raged through their home last week, Pascoal and Sophia Pereira moved to sleep on the kitchen table and waited calmly for the waters to subside.
This time, though, the waters didn't fall. The torrent grew higher and the elderly couple fled to the top of their wardrobe. When it rose further still they clambered onto the support beam under the roof.
Inch by inch, the waters rose, threatening the Pereiras with a watery grave.
But after four days of such agony, help was finally at hand yesterday. A boatload of Dutch aid workers came scouting around the vast expanse of the flooded plain for survivors.
Someone heard a knocking sound, forced the door and found the elderly couple, their hands entwined and on the point of collapse. Hour by hour, such small dramas are being played out across Mozambique's submerged provinces as the search for survivors grows ever more desperate. This is a battle against overwhelming odds, as half a dozen helicopters take on the task of searching an area as large as Ireland.
Seen from the air, the zone of flooding stretches right to the horizon. Towns and villages have been wiped out, leaving hardly a trace of human life peeping out above the muddy brown waters.
Giant trees have shrunk to the size of shrubs, so deep are the waters. And only the highest roofs glint in the hot sun.
At Chibuto, 100 miles north east of Maputo, South African army helicopters deposit the survivors plucked from roofs and treetops. Hungry , exhausted, soaked, they stumble down onto firm ground for the first time in days. One man has saved a chicken, all carry their few remaining possessions on their backs.
"Everything I have is gone," says Lorenzo , before collapsing on the ground, a pathetic figure half naked after four days on top of a tree. "It was like in the middle of a dam when the water came," he says. The heroes of the hour are the pilots of the South African defence forces, swaggering white officers who were once the archenemies of Mozambique.
In a few hours yesterday we watched them bring in dozens of survivors, each one patiently winched aboard the helicopter in a time-consuming and highly dangerous operation.
Which raises the question: where is the rest of the rescue operation?
