"And everything that's gone through its path, yep," the Doctor said. He struggled, holding back a sudden wave of despair. "But the TARDIS wouldn't have gone through that," he added, more for his own benefit. "It would've taken the Vortex, which circumvents the path of the Wall."

Jack's other question was more difficult. "Stopping a Space Wall isn't like knocking down a garden brick pile. It's a planet-sized killing machine that will stick and consume you with the slightest touch. But..."

He went through a few calculations in his mind, then turned to make a run for it. "We've got to get the survivors off of this ship!"