However, the two were able to tell for themselves before getting back to the Albireo.
The flow didn't stop all at once, of course; but with the valley feeding it blocked off by a pile of volcanic ash four hundred feet high on one side, nearly fifty on the other and more than a quarter of a mile long, its enthusiasm quickly subsided. It was thin, fluid stuff, as Burkett had noted; but as it spread it cooled, and as it cooled it thickened.
Six hours after the blast it had stopped with its nearest lobe almost a mile from the ship, less than two feet thick at the edge.
When Mardikian's tractor arrived, Burkett was happily trying to analyze samples of the flow, and less happily speculating on how long it would be before the entire area would be blown off the planet. When Marini's and Harmon's vehicles arrived, almost together, the specimens had been loaded and everything stowed for acceleration. Sixty seconds after the last person was aboard, the Albireo left Mercury's surface at two gravities.
The haste, it turned out, wasn't really necessary. She had been in parking orbit nearly forty-five hours before the first of the giant volcanoes reached its climax, and the one beside their former site was not the first. It was the fourth.
"And that seems to be that," said Camille Burkett rather tritely as they drifted a hundred miles above the little world's surface. "Just a belt of white-hot calderas all around the planet. Pretty, if you like symmetry."
"I like being able to see it from this distance," replied Zaino, floating weightless beside her. "By the way, how much bonus should I ask for getting that idea of putting the seismic charges to use after all?"