The Doctor strode around in a wide circle, or at least as wide as he could manage in between all the birds and people and equipment. "So, extrapolating from what we know, the likely scenario is that someone -"
"Let's call him the Pirate," put in Donna. "Arrr!"
River rolled her eyes. "How exciting."
The Doctor gave them both a brief intense stare, as if questioning their sanity, before continuing. "Someone managed to not only find out about the nanobots and their gold-making propensities, but also discovered their location, travelled through space to get there, and had the technical know-how to actually break through that forcefield and reseal it afterwards. And believe me, those Shadow Proclamation forcefields carry some clout."
"How do we know they sealed it up again?" asked Karanga.
"Because they didn't take over the universe yet."
"Oh, great," said Donna. "So we're on borrowed time."
"It's not so bad," said the Doctor. "Well...at least, not as bad as it could be. Not yet." He bounced up and down on his heels and pouted.
River huffed. "The hole's only getting deeper, love. Best just stop talking until that genius brain of yours gets itself untangled."
The Doctor gaped, fish-like, and started a couple of words that ended up not going anywhere.
River ignored him and turned to Donna. "We're definitely safe for now, my dear. Using a code reader, I was able to determine that this bot was part of a smaller swarm after it left the forcefield. The small swarm is still growing, but obviously not at the sheer volume of the other."
Donna gulped. "Okay, let me get this straight. Someone - our pirate - opened the forcefield, let some nasty creepies out, and closed it up again. So what's the problem - aside from tut-tutting about a morally corrupt thief?"
"Ah," said the Doctor, but River cut in.
"Because what pirate would be content with a tiny portion of that astounding hoard?
The Doctor finally regained his power of speech. "The question is, how big is that new swarm?"
"Well," said River, "I was hoping for some help from that great big head of yours. My swarm sensor needs some Timelord tweaking."
"Okay. Show me."
River tapped a pattern on the screen and a complicated code filled it and continued to scroll. The Doctor said no more for the time being, but bent over the display.
"Honestly, you two are like an old married couple." said Donna.
"You're very perceptive, bright one." River turned an appraising gaze on her.
"There," said the Doctor. "I've synced the algorithm matrix to the polarising capacitor." He waved the buzzing sonic screwdriver over it. "and upped the frequency range to tthe widest known." He grinned. "Now you should be able to pick up just about everything in the universe."
"Thats a bit rich, even from you," said River, and flicked back from the code to operational view. Her jaw dropped fractionally and Donna moved to peer over her shoulder.
"What is it?"
"We really can see all of known space on this thing. Was that necessary? Just the outer galaxy arm would have been enough."
The Doctor tried unsuccessfully to repress a smile.
"You naughty boy, you'll use up all their power," said River, inclining her head towards their hosts.
"Let's hurry and find what we're looking for, then," said Karanga from her spot on the table.
Stars and planets whooshed by on the screen. All appeared in comforting shades of blue.
"Inputting coordinates," said River. The display turned as if it were the viewscreen of a spaceship, so abruptly that Donna fought a shred of vertigo at the sense of whirling in space. It streaked past stars and slowed as it zoomed in on a dot that grew to swallow the view, alive with red.
"Okay, we found our golden star," said River.
"Actually, it's a yellow dwarf," said the Doctor. "Not unlike Sol."
Donna peered at the reading. Aside from solid red there was another cluster of it, moving through space some distance from the mother system. "Look at that," she said, pointing.
"Yep, that's the new swarm. Escapees."
"But what's that other thing chasing it?" asked Donna. The new object had only a spot of red in a smooth blue shape.
"I think we found our pirate, said the Doctor, "and whoever it is, he's pretty close to the forcefield. He could try to break it open again at any time, which we do not want to happen."
Donna set her fists on her hips. "There's only one thing for it." She turned to River.
River nodded, eyes blazing. "To the TARDIS!"