Donna looked over to where Terry was just watching the Ood, silently letting her tears fall down her cheeks, and she couldn't bear it any longer. Seeing the Ood on top of hearing them was too much and the tears fell from her eyes too as she begged the Doctor, "Take it away."

"Sure?" The Doctor asked softly, and Donna whimpered.

"I can't bear it."

Not surprised, the Doctor gently turned Donna away from the Ood so she was facing him again. He touched her temples again, removing the mind meld and disconnecting her from the telepathic field that the Time Lords had no way of escaping. And in a morbid way, they didn't want to. Because they knew that the pain they were feeling was only a fraction of what the Ood felt.

Donna understood that as well and she sniffed. "I'm sorry."

"It's okay." The Doctor murmured as he moved back to the cage. He drew Terry into his arms and she rested her head against his chest while Donna continued to cry behind them.

"We'll save them, angel. This time, we won't leave them. I promise." The Doctor swore as he held Terry tightly against him while they both stared at the Ood.

"Yes, we will." Terry agreed, listening to the Doctor's strong heartbeats under her ear. The sound soothed her unsettled spirit and Terry took deep breaths while from behind, Donna whispered between her tears.

"How often can you two hear things like this?"

"All the time." The Doctor admitted softly, still watching the Ood.

The Ood had huddled even closer together and Terry finally lifted her head off the Doctor's chest. Taking his sonic, she moved to open the cage the Ood were trapped in just as a loud metal clang sounded above them. Donna looked back in alarm.

"They're breaking in." She realized and the Doctor scoffed.

"Ah, let them." The Doctor said scornfully as he pushed the now unlocked cage door open while Terry dropped his sonic back in his pocket for him.

The Ood cowered away from them fearfully as the trio entered the cage. It broke a piece of Terry's hearts but she forced herself to bend down with the Doctor as he knelt before the Ood. He noticed the way they seemed to be bowed over their hands so he decided it was as good a place to start as any.

"What are you holding?" The Doctor questioned the nearest Ood gently.

The Ood cowered away at his question, hiding his hands.

"Show me." The Doctor murmured softly, his tone soothing.

"It's okay. We're friends." Terry added gently.

The Ood peered at her and then the Doctor as he introduced their little group. "Doctor, angel, Donna. Friend."

The Ood seemed to deliberate but some of the tension had left the alien. Sensing they were making progress, the Doctor said encouragingly, "Let me see. Look at me. Let us see."

The Ood slowly came forward at the Doctor's urging and the Doctor nodded.

"That's it." The Doctor murmured. "That's it, go on. Go on."

The Ood slowly held out his hand before removing one palm to reveal a small, pale red organ in his other palm. The palm that the translator balls typically sat in. Terry closed her eyes; she'd known this was coming but it did nothing to stop the heartbreak seeing the real thing caused.

"Is that…?" Donna gasped, unable to finish in her horror.

"It's a brain." The Doctor breathed in confirmation as he stared at the organ. "A hind brain. The Ood are born with a secondary brain. Like the amygdala in humans, it processes memory and emotions. You get rid of that, you wouldn't be Donna any more. You'd be… like an Ood. A processed Ood."

"So the company cuts off their brains?" Donna asked, still in shock at the horrific truth that both she and the Doctor finally knew.

"And they stitch on the translator." The Doctor confirmed through gritted teeth.

"Like a lobotomy." Donna whispered. She then shook her head shakily.

"I spent all that time looking for you, Doctor, angel, because I thought it was so wonderful out here."

She stared at the Ood mournfully.

"I want to go home." Donna whispered and Terry opened her eyes.

Just then, a loud crash sounded above them.

"They're with the Ood, sir." A guard's voice called.

Instantly, the Doctor shot to his feet and hurried to the door. He grabbed it and swung it shut to lock him and his two companions inside with the Ood just as the head of the factory, Halpen, and Dr. Ryder arrived with a few guards. The guards instantly pointed their guns at the Doctor and Terry, who had stood up behind her boyfriend. And her glare was almost as dark as the Doctor's despite her tear-blotched face as the Doctor spat furiously at the monsters who surrounded them.

"What you going to do, then? Arrest me? Lock me up? Throw me in a cage?"

He gestured at the cage holding him and Terry and Donna with the Ood.

"Well, you're too late. Ha!"

"Ow!" Donna hissed in protest as she was cuffed mercilessly to a pipe in Halpen's office.

Terry and the Doctor were quieter as they were also handcuffed although their dark glowers said everything as they glared at Halpen who just sneered back at them.

"Why don't you just come out and say it?" Halpen sniffed. "FOTO activists."

"If that's what Friends Of The Ood are trying to prove, then yes." The Doctor answered without missing a beat.

"The Ood were nothing without us," Halpen answered scornfully. "Just animals roaming around on the ice-"

"Only an idiot would think that someone who doesn't speak with words is the same as an animal." Terry snapped. "And don't even get me started on the fact that you shouldn't even treat animals the way you have these Ood."

"Let me guess: you're also a vegetarian." Halpen said with an amused child like an obnoxious adult speaking to a child. "You don't know what you're talking about, girl. They welcomed it. It's not as if they put up a fight."

"You idiot." Donna spat, and Halpen's smile dropped at the deep malice dripping in the redhead's voice. "They're born with their brains in their hands. Don't you see, that makes them peaceful? They've got to be, because a creature like that would have to trust anyone it meets."

"Oh, nice one." The Doctor muttered appreciatively, giving Donna an approving nod.

"Thank you." Donna murmured back but Halpen was much less impressed.

"The system's worked for two hundred years." Halpen snarled at them. "All we've got is a rogue batch. But the infection is about to be sterilised."

Terry's expression darkened while the Doctor frowned as Halpen activated his wrist comm.

"Mr. Kess. How do we stand?"

"Canisters primed, sir." A voice reported back. "As soon as the core heats up, the gas is released. Give it two hundred marks, and counting."

The Doctor couldn't believe what he was hearing.

"You're going to gas them?" The Doctor asked incredulously and furiously.

Dr. Ryder shifted a little uncomfortably, but Halpen was unconcerned.

"Kill the livestock. The classic foot and mouth solution from the olden days. Still works."

"You're not human." Donna cried and Halpen smirked at her.

"Oh, I think you'll find," Halpen sneered, "that I am very much human."

"And I think you'll find," Terry interrupted darkly. "That you're nothing but an ignorant, puny-brained moron who has no idea when he's long crossed a line that no one should ever cross."

Halpen shot her an annoyed look but it turned to confused alarm as an alarm suddenly started blaring loudly all over the factory.

"What the hell?" Halpen demanded, looking around wildly just as they all heard gunfire from outside.

Halpen's jaw clenched and he nodded at Dr. Ryder and his personal guard to follow him outside. They left for Halpen to investigate the disturbance, leaving the Doctor and the others with only a few guards. Donna glanced at her friends.

"What do you think is happening?"

"It must be the Ood." The Doctor replied just as Halpen returned.

"Change of plan." The man declared to Dr. Ryder, who looked rather anxious as he read off a portable computer.

"There are no reports of trouble off-world, sir. It's still contained to the Ood Sphere."

"Then we've got a public duty to stop it before it spreads." Halpen ordered, when the Doctor interjected sharply.

"What's happening?"

Halpen looked over at the Time Lord and he said in a calm but no less spiteful tone than before, "Everything you wanted, Doctor."

The Doctor's eyes narrowed angrily and his glare intensified, but Halpen went on in his usual, unconcerned manner.

"No doubt there'll be a full police investigation once this place has been sterilised, so I can't risk a bullet to the head."

Terry made a noise of disgust and Halpen smiled.

"I'll leave you to the mercies of the Ood." He said simply before stalking off.

"But Mr. Halpen," the Doctor called after the man sharply. "There's something else, isn't there? Something we haven't seen."

The other man stopped, whirling around to stare at the Doctor, while Donna asked in confusion, "What do you mean?"

"The Ood couldn't survive with a separate forebrain and hind brain." Terry explained for the redhead's benefit. "They'd be at war with themselves."

"There's got to be something else."The Doctor took over, his eyes on Halpen alone. "A third element, am I right?"

Halpen sneered. "And again, so clever."

But the Doctor just spoke over him. "But it's got to be connected to the red eye. What is it?"

Halpen's cool façade finally cracked and his face scrunched with fury as he strode over to stand toe-to-toe with the Doctor.

"It won't exist for very much longer." He hissed, glaring at the Doctor, before he withdrew.

"Enjoy your Ood." Halpen called mockingly as he left the building with Dr. Ryder and all the guards. Terry scowled while the Doctor growled. But they did have some pressing matters on their hands.

"Come on." The Doctor urged as they started wriggling in an attempt to free themselves. Well, the Doctor and Donna tried.

"Well, do something." Donna bit out as she tried and failed to break free of her handcuff. "You're the one with all the tricks. You must have met Houdini."

"These are… really good handcuffs." The Doctor answered irritably as a trick he'd attempted failed.

"Oh well, I'm glad of that." Donna snapped. "I mean, at least we've got quality!"

It was then that she noticed Terry was unusually calm and unmoving.

"What are you doing, angel? We've got to get free!" Donna cried but Terry shook her head.

"I'm waiting for that."

The Doctor looked over, puzzled, before his head whipped around toward the door to the office as it opened. Three Ood stepped inside, their eyes red and their translator balls lifted menacingly.

"We're doomed." Donna cried but Terry snapped her fingers to force Donna to focus even as the Doctor quickly spoke to the Ood.

"Doctor, Terry, Donna, friends."

"The circle, Donna." Terry said at the same time the Doctor was speaking. Donna took her advice and shouted the first words she could think of.

"The circle must be broken."

But the Ood didn't respond, simply coming even closer.

"Doctor, Terry, Donna, friends." The Doctor cried as he tried to push Terry back behind him.

Donna shouted at the same time in a panicked tone, "The circle must be broken."

"Doctor, Terry, Donna, friends!"

"The circle must be broken."

"Doctor, angel, Donna." Terry interjected in a calm voice, ignoring as the Ood lifted their translator balls and brought it right in front of their faces. "Friends. The circle must be broken."

"The circle must be broken!" Donna parroted in a scream.

And just like that, the Ood stopped advancing. The Doctor and Donna stared with wide eyes as the Ood cocked their heads before the lights in their translator balls clicked off. Terry meanwhile stepped forward before being jerked back accidentally as her cuff pulled her back while the Ood grabbed their heads. It was like they were listening to something in their minds… and then they straightened up.

"Doctor." The Ood said in their normal voices. "Angel. Donna. Friends."

"Yes." The Doctor gasped. "That's us. Friends. Oh, yes!"

He laughed gleefully but Terry tugged his hand in hers.

"Doctor, we don't have time." She turned to the Ood. "Can you help us? We have to hurry to break the circle."

The Ood were quick to help. As soon as they were free, Terry and the Doctor led the way in running out of the office. It was a minor warzone outside as soldiers fired at any moving object while the Ood all attacked the soldiers, overwhelming them with sheer numbers.

"This way!" Terry called as she led the way into the factory complex.

"What are we looking for?" Donna cried.

"Something underground. Like some sort of cave, or a cavern, or-"

He broke off as Terry started to lead them down somewhere when something exploded right behind them. The trio went flying as a result of the blast and Terry found herself half-buried in the snow in the next second. She twisted and popped her head back out of the snow just as the Doctor and Donna popped up beside her.

"All right?" The Doctor checked. The others nodded, and the Doctor glanced back to try see what had happened. But he stopped, blinking in surprise as an Ood stood right in front of them, staring down at them with his head cocked. A very familiar Ood. But most importantly, his eyes were normal.

Terry smiled at Halpen's 'personal assistant'. "Ood Sigma."

Ood Sigma led them into Warehouse 15. The Doctor soniced the door controls, causing them to spark and the door slid open at once. The Doctor quickly led the way inside while Terry led the way down the catwalk into a red-lit room. Only to stop and clutch her head halfway there.

"Terry?" Donna cried in concern.

"My head." Terry grimaced as the singing got louder in her head. The Doctor was wincing as well but he reacted less to the raw pain of the singing as he saw something below the catwalk. The source of their current pain and the whole reason the Ood were singing in the first place.

"Oh…" The Doctor breathed and Donna looked up from Terry.

"What- oh."

Donna stared down at the giant brain sitting below, pulsing slightly while an electric current circle buzzed around its exterior.

"The Ood Brain." The Doctor breathed, understanding dawning at last. "Now it all makes sense. That's the missing link. The third element, binding them together. Forebrain, hind brain, and this, the telepathic centre. It's a shared mind, connecting all the Ood in song."

"And there's only one reason they're singing what they are right now." Terry muttered darkly as she shook with pain.

The Doctor was about to respond when a voice called suddenly, "Cargo."

The Doctor whirled around to face Halpen, who stood at the far end of the catwalk with a gun trained right on the Doctor.

"Cargo." He replied lightly, his tone not matching his expression. "I can always go into cargo. I've got the rockets, I've got the sheds. Smaller business. Much more manageable, without livestock."

"He's mined the area." Dr. Ryder explained helpfully as he appeared behind Halpen.

"You're going to kill it?" Donna asked in disbelief. Sure, she didn't have a high opinion of the man. But she certainly hadn't thought he could sink any lower.

Halpen shrugged as he walked closer to the group, his gun still pointed at the Doctor.

"They found that thing centuries ago beneath the Northern Glacier."

"Those pylons." The Doctor explained quietly for Donna's sake.

She glanced at the current around the brain and Donna realized, "In a circle. The circle must be broken."

"Damping the telepathic field." The Doctor snapped at Halpen. "Stopping the Ood from connecting for two hundred years."

Halpen ignored the criticism as he glared at the Ood behind Donna.

"And you, Ood Sigma," Halpen said scathingly. "You brought them here. I expected better."

"My place is at your side, sir." Ood Sigma replied diffidently as he walked over to stand beside Halpen, who sneered.

"Still subservient. Good Ood."

Terry almost said something - almost. But she refrained, lest she give them all away, as Donna instead demanded, "If that barrier thing's in place, how come the Ood started breaking out?"

"Maybe it's taken centuries to adapt." The Doctor answered, his eyes never leaving Halpen. "The subconscious reaching out?"

"But the process was too slow." Dr. Ryder interjected suddenly and they all stared at him, Halpen included. Well, almost all. "It had to be accelerated."

He turned to Halpen, growling, "You should never give me access to the controls, Mr. Halpen. I lowered the barrier to its minimum."

Halpen gaped, truly shocked, while Ryder continued to explain darkly.

"Friends Of The Ood, sir. It's taken me ten years to infiltrate the company, and I succeeded." He lifted his chin defiantly.

Halpen paused before glancing behind Ryder and then he sneered.

"Yes. Yes, you did."

With that, Halpen started forward; but Terry was faster. She lunged and before Halpen could even think to shift his aim from the Doctor to her, she had grabbed him before he could push Ryder off the catwalk.

"Angel!" The Doctor and Donna cried as Terry wobbled dangerously at the catwalk edge while she struggled against Halpen and Ryder looked on with alarm.

"Look out!" Ryder yelled as Halpen's gun waved around wildly.

Donna looked around automatically, seeking a way to help, while the Doctor just jumped in to help Terry. He managed to disarm Halpen as Terry stomped on his foot viciously while at the same time clawing his balding head. The man howled as he was forced to let go of his gun between the pain and the Doctor's tight grip around his hand. Terry kicked it away quickly and the gun fell off the far side of the catwalk, landing uselessly with a clatter beside the Ood brain. The Doctor meanwhile dragged Terry back with him as Halpen grasped his receding hairline and he glared murderously at the pair as they rejoined Donna while Ryder stood a little to the side.

"You tried to kill me!" Ryder cried indignantly and Halpen snarled, "Yes, well done for pointing out the obvious!"

"You tried to kill me!" Ryder repeated, now growing furious.

"What did you expect? He's heartless enough to try and create an empire out of torturing Ood, it's not exactly rocket science to guess he'd be okay with killing people too. Especially after he already tried to kill us." Terry snapped irritably. Her head was aching as the Ood song continued to ring in her head and she grimaced while Halpen's glare darkened.

"I'll kill you. I'll see you dead myself!" He snarled, starting to take a step forward despite being hopelessly outnumbered. But he was interrupted by the most unlikely person.

"Would you like a drink, sir?" Ood Sigma asked, holding out a glass of clear liquid.

"I think hair loss is the least of my problems right now, thanks!" Halpen thundered, throwing a dirty look over his shoulder at the Ood.

But Ood Sigma just stepped closer as he said as politely as always, "Please have a drink, sir."

"If," Halpen stuttered, blinking strangely all of a sudden. Terry smirked with grim satisfaction as she waited for the penny to drop. "If you get in my way, I'll kill you too."

His 'O's elongated strangely, like his mouth was working extra hard to speak properly. The Doctor frowned as he observed the scene before them while Ood Sigma simply repeated, "Please have a drink, sir."

Halpen's eyes widened as he finally realized what was going on.

"Have, have you poisoned me?" He gasped, staring with horrified eyes at the glass Ood Sigma held.

"Natural Ood must never kill, sir." Ood Sigma answered politely. That in itself was an answer enough.

"What is that stuff?" The Doctor asked suspiciously, also eyeing the glass Ood Sigma held. The Ood was only too happy to reply.

"Ood graft suspended in a biological compound, sir."

"What the hell does that mean?" Halpen demanded as he clutched his balding head like he had an exceptionally bad headache.

"Oh, dear." The Doctor breathed. He glanced down at Terry, torn between impressed and alarmed.

She was decidedly less distressed as she folded her arms across her chest while Halpen barked at them, "Tell me!"

"You reap what you sow, Mr. Halpen." Terry answered, watching him closely as she waited for the tell-tale signs that the conversion process was ending. "You tortured and murdered the Ood, so they started to adapt. Their subconscious started to break through the barrier you placed on them. For some, that was reflected in the red eye as revenge. Others, it was becoming rabid with anger. But most of all there was patience."

She looked right at Ood Sigma and the others did the same in awe.

"You shouldn't have made the most intelligent and merciful of them all, your personal servant, Mr. Halpen." Terry looked back at the man as he stared in stunned silence. "You thought they were barbarians; no, you called them animals, didn't you? And you never realized that all this time, you were the moron who couldn't recognize the more intelligent being even when you were literally staring him in the face."

Halpen's eyes were bulging by now and he screeched, "What have you done?"

But his speech was warbling even more as the process reached completion.

"So sorry about the hair loss, sir." Terry mocked while the Doctor leaned back on the balls of his feet.

"With you standing right next to the Ood Brain, I wonder, Mr. Halpen, if you can hear it yet? Listen." The Doctor paused to let the singing swell between those who could hear it.

Halpen was gasping now and trembling violently.

"What have you…? I'm not…"

"Do you really need us to spell it out for you?" Terry asked. "Fine. Conclusion? You're not so human after all, Mr. Halpen."

Halpen gaped and then he gagged. His face suddenly went blank and his hands rose as if of their own accord to his head. He peeled back the skin off his head, tentacles pouring out of his mouth as he did, and when he straightened up-

"They," Donna gasped out, looking a little green. "They… turned him into… an Ood?"

"Yep." The Doctor nodded as they all stared at the now fully Ood Halpen.

"He's an Ood." Donna repeated in revulsion.

"I noticed." The Doctor answered shortly.

"He's not done yet." Terry observed as they watched Ood Halpen groan.

"What do you mean-?"

Donna's question was answered when Ood Halpen suddenly spat into his hands. A small hind brain plopped down into his palms and Donna gagged. Ryder ran out and they all heard him vomiting into the snow. Terry just patted the redhead beside her absently as she watched Ood Sigma turn around to face them.

"He has become Oodkind, and we will take care of him." The Ood explained. Donna shook her head.

"It's weird, being with you two." She admitted, sounding almost dizzy. "I can't tell what's right and what's wrong any more."

"It's better that way." The Doctor advised her. "People who know for certain tend to be like Mr. Halpen."

Donna turned a darker shade of green again, but a beeping sound alerted the Time Lords to another pressing issue.

"Oh!" The Doctor quickly leaned over the side of the railings and he deactivated the beeping bombs there in a few swift moves. "That's better. And now!"

He turned and dashed toward a computer console on the side of the room, calling over his shoulder.

"Sigma, would you allow me the honour?"

"It is yours, Doctor." Sigma answered warmly.

"Angel?" The Doctor asked and Terry chuckled, finally relaxing.

"I stole the spotlight earlier - seems only fair you steal it now." Terry answered.

The Doctor grinned before he turned to the console with beaming satisfaction. "Oh, yes! Stifled for two hundred years, but not any more. The circle is broken. The Ood can sing."

He slammed his hand on a button, shutting down the current around the Ood brain. Terry closed her eyes in relief as the singing stopped in her head; before it started again, slower than before but so much lighter and brighter than it had been before. And now that the Ood weren't limited, their singing wasn't just limited to a telepathic field.

Donna gasped as she heard the singing and she cried in awed delight, "I can hear it!"

She looked to the two Time Lords who just smiled back at her as Ood Sima lifted his hands as he began singing too.

Only a short while later, the three travellers stood with a small group of Ood outside the Tardis.

"The message has gone out." The Doctor said in a satisfied voice. "That song resonated across the galaxies. Everyone heard it. Everyone knows. The rockets are bringing them back. The Ood are coming home."

"We thank you, Doctor Angel Donna, friends of Oodkind." Ood Sigma said warmly, using his translator ball. But it no longer lit up the way it had while they were captive and Terry beamed.

Her smile dimmed however when Ood Sigma asked, "And what of you now? Will you stay? There is room in the song for you."

"Oh, I've," the Doctor excused quickly. "I've sort of got a song of my own with my angel and, and, thanks."

The Doctor nodded back at the Tardis to show what he meant. Terry smiled slightly but it faltered when Ood Sigma stated rather abruptly, "I think your song must end soon."

The Doctor frowned. "Meaning?"

"Every song must end." Ood Sigma answered vaguely.

A flash appeared behind Terry's eye and a vision passed through her mind's eye - the Doctor staggering through the empty streets of London, headed back into the Tardis for his regeneration. But something was wrong. It should never have happened. Why should it not have happened? Eleven existed, of course Ten had regenerated like Nine had. But it shouldn't have happened.

"Right."

Terry was broken from her thoughts as the Doctor turned away from the Ood to address Donna.

"Er, what about you? You still want to go home?" He questioned and Donna gave him a small smile.

"No." The redhead answered firmly. "Definitely not."

"Then," the Doctor smiled as he turned to the Ood. "We'll be off."

Ood Sigma nodded. "Take this song with you."

The Ood lifted their hands as they sang the bright song of freedom, and Donna's smile widened.

"We will." She promised.

"Always." The Doctor added and Ood Sigma called after them in farewell.

"And know this, Doctor Angel Donna. You will never be forgotten. Our children will sing of the Doctor Angel Donna, and our children's children, and the wind and the ice and the snow will carry your names forever."

That made them smile again before the trio turned and headed back into the Tardis. But before she entered the Tardis, Terry looked back. She looked at the Ood as they sang for her and then her eyes moved to the snowy mountains in the distance. And for some reason, in that moment when a sense of foreshadowing washed over her, the Minotaur's words from the 'God Complex' adventure came back to her.

"So, run, if you will; run, until you can run no further. Until the time comes, Daemon, born of fire, of ash, of last glimmering hope."