"I beg your pardon?" said Sarah Jane.
"At this time of year on this continent of Plennigass II," said the Doctor, the ends of his scarf attracting leaves and twigs as they proceeded through the forest, "the bloodtit mating season should be in full swing. But there's no birdsong."
"Oh," said Sarah Jane. "I thought you meant," said Sarah Jane. "What could stop the birds' mating season?" she asked.
"Only an ecological anomaly of staggering proportions."
--
Pliggle staggered into the underground control room under the proportions of the crate he was carrying. "I got na ftuff," he said, his face pressed against one side of the crate to keep it balanced.
Duke Plart turned from the console where Plujj was monitoring the progress of their plot across the planet. "That's not all of it!"
"How muffk tyou fink I kin carry?" Pliggle groaned, belatedly adding, "Yer Lordfip."
"Where's the rest?"
"Atta docking bay. Ploor 'n' Plakk're helpink me move it to the aerodrome."
"Smartly, then," said Duke Plart.
--
"There!" cried the Doctor as they emerged from the woods. "What did I say?"
About five miles off over grassy plains there was a large black cloud. "You think that cloud's artifical?" Sarah Jane asked.
"The sharp-edged rectangular shape is rather telling, I'd say. Come along."
The Doctor started off across the plains. Sarah Jane eyed their destination warily. Just looking at the distance made her ankle hurt.
--
Pliggle banged back through the underground control room's door, still carrying the first crate, about half an hour later.
"Remint me hwere na aerodrome is," he said.
"Well, let's see," said Duke Plart. "This is an underground secret installation. An aerodrome is for machines that fly in the sky. Where is an interface between under ground and the sky likely to be?"
"Err ... grount level?" Pliggle guessed.
"Very good. Now - off you go." Duke Plart made a little walking motion with his hand, like his fingers were legs walking.
"Gotcha," said Pliggle. He wobbled back out.
"What a git," said Plujj. "Is that the best you could do for henchmen?"
"I like the foolish ones," said the Duke. "Can't plot against you without your knowing."
Plujj laughed, but it died away abruptly halfway through.
--
About a quarter of the way to the cloud Sarah Jane tripped over a Plennigast hidden on the ground in the tall grass.
"Sarah!" called the Doctor, rushing back at her cry, having gained several hundred yards on her. He found her sitting on the ground next to the unconscious native, whose skin was an unusual shade of blue. "Something's terribly wrong here!"
"It's all right," said Sarah Jane, flexing her ankle. "It seems fine. Does it look all right?"
The Doctor was patting the native's cheeks, trying to revive him. "Wake up! What happened? Who did this to you?"
The native opened his eyes and said, "The," and died.
--
"We may be in trouble," Plujj hissed to his co-conspirators at the next fifteen-minute break.
"Everything's going perfectly," Plakk objected.
"Duke Plart says," explained Plujj, "he picks his henchmen for foolishness so that they can't plot against him without his knowing."
Plakk and Ploor exchanged glances for several seconds.
"He's - what's the word - bluffing," said Plakk.
"He's just trying to scare you," said Ploor.
"Why is he trying to scare me if he doesn't know we're plotting against him?"
"Look, he's the idiot, okay?" Ploor insisted. "Now let's get back to work. Duke Plart wants all that stuff moved to the aerodrome. Oh, and Plujj, he wanted the cassette from the break room security camera - would you take that to him please?"
--
About halfway to the cloud Sarah Jane tripped again. The root cause, again, oddly wasn't a root but another Plennigast, of the same unusual shade of blue, twitching in the long grass. She clambered back to her feet with no trouble. "I really am having remarkable luck today, aren't I?"
The Doctor grabbed this Plennigast by the lapels of her nastaponaw and tried to shake her awake. "Who did this to you? What's happening on this planet? What's the capital of South Dakota?"
"Dark," she said, and died.
"Silly name for a state capital, don't you think?" said Sarah Jane.
The third dying Plennigast Sarah Jane tripped over said "is" before he died being shaken in the Doctor's arms.
"Why would they each take up the same sentence where the last one left off?" Sarah Jane asked, silently wondering whether the Plennigast had died of whiplash.
"A side effect of this Dark," said the Doctor, "must be the creation of a group mind among a species, to whom this is all the same conversation. If a bit disjointed. That would also explain why the bloodtits are so silent. No need for song when you can see into a prospective mate's mind."
"Doesn't another side effect of this Dark seem to be death?" Sarah Jane suggested. "Mightn't that explain the bloodtits' silence too?"
"I doubt it."
"Why?"
"Have you tripped over any bloodtits yet?"
"No. ...What could that mean?"
"That's too horrible to think about."
--
"The cloud has now extended to a radius of ten miles around the generation point," reported Plujj.
"Very good," said the Duke. "That is, if Pliggle and the others have already finished setting up the equipment at the aerodrome."
"They should have been long done by now, your Lordship."
"Good. You see," said the Duke, "this installation is only 9.9 miles from the generation point."
"Say, that's right."
"Pliggle, Ploor and Plakk ought to have been busy dying for, oh, five minutes now."
Plujj gulped. "Small loss, though, if they were all that foolish, right, your Lordship?"
"They had their uses. And so do you. Just pop out there and see whether they're quite finished off, would you?"
"Yes, your Lordship."
--
The Doctor and Sarah Jane approached the borderline of the land shadowed by the cloud trepiditiously. The Doctor assured Sarah Jane that Plennigast physiology was too different from his and hers for anything that affected the natives to harm them, then wrapped the end of his scarf around his mouth and nose.
Several yards into the dark area, near an array of dish antennas, Sarah Jane tripped over three Plennigast rolling around in agony and in that same unusual shade of blue.
"The Dark is what?" the Doctor shouted at them.
"Coming!" they all cried before dying. Sarah Jane had just regained her feet, but one of them rolled into her in his death throes. There was a loud snap, and Sarah Jane dropped to the ground screaming a blasphemous crudity.
"'The Dark is coming'," said the Doctor. "I can see that."
Sarah Jane loudly and impolitely requested assistance from the Doctor, while at the same time loudly and impolitely questioning the legitimacy of the birth of the deity of the religion in which she had been raised. From his pockets the Doctor took an Ace bandage (which he was tempted to rename a 'Sarah Jane Smith' bandage), a collapsible splint, a pair of collapsible crutches, and a collapsible dose of polydimorphine.
The Doctor was just putting the finishing touches on the wrapping of the bandage, and Sarah Jane was just getting to the stage of polydimorphine reaction when she could have got up and walked off splintless without noticing there was anything wrong, when a piece of ground nearby rose on a hinge. From a secret passage came a Plennigast, this one the usual shade of blue. He had a scarf covering his mouth and nose.
"He's mad!" the Plennigast said.
"Mad? Nooo, the Doctor just has no clothes sense," said Sarah Jane. "You're really a good guy, aren't you, Doctor? Do anything for your friends, wouldn't you? Got any more of that morphing Polly-dye stuff?"
"He sent me up here to die, like they did!" said the Plennigast, pointing at the three dead Plennigast who had finally succeeded in crippling Sarah Jane.
"Who did, Plujj," the Doctor asked, "Duke Plart?"
"How did you guess?" Plujj gasped. "How do you know who I am?"
"Your nametag reads PLUJJ and is in the shape of the Plart crest."
"Oh," said Plujj. "Anyway, he's got to be stopped! It's a fiendish, devilish, outlawish, nastyguyish thing he's doing!"
"How do you know what he's doing?"
"I've been helping."
"Ah, but you draw the line at dying on command."
"I may be foolish, but I'm not stupid."
--
Duke Plart looked up as Plujj led the Doctor and Sarah Jane - who was whistling How Much Is That Doggie In The Window? - into the control room. "You want something done right, do it yourself," he sighed, resignedly pulling out a hand projectile weapon and shooting Plujj through the right knee.
"Plennigast surgical technology can't replace knees either?" Sarah Jane asked.
"You could say that," said the Doctor. "That's where their brains are."
"You're that Doctor I met yesterday at the capital," said the Duke.
"Of South Dakota?" asked Sarah Jane, and burst out laughing.
"Please pardon my friend," said the Doctor, "she's out of her mind from the pain."
"Oo oo yes, it's time for my medicine, right, Doctor?"
"You're either here to try to stop me or to muscle in on the action," said Duke Plart. "Either way, I'm going to kill you."
"But first," prompted the Doctor.
"But first," acceded Duke Plart.
"There's always a 'but first'," snickered Sarah Jane. She was learning.
"- First I want to know why you're here."
"Obviously I'm not here to join forces with you," said the Doctor. "You can't have done this yourself. The technology doesn't exist that could generate that dark cloud in Plennigass' high-psitrichlorinatide atmosphere against the mental defenses of the planet's guardians. Or, as I should obviously say, its former guardians."
Duke Plart's composure faltered. "You can't mean -" Abruptly he shouted as if answering an unheard voice, "No! You need me, not him!"
"I know who you are!" The Doctor shouted to the ceiling too. "Show yourselves!"
Two small avian creatures flew into the room, one alighting on each of Duke Plart's shoulders. Several more, each half the size of the first two, began circling the room in holding patterns. Their coloration was a uniform deep red.
"Let me guess," giggled Sarah Jane, "are those bloodtits?"
ROLL CREDITS