“Martha, how did they get you?” Sarah Jane asked. “You were in China.”

“China?” Martha looked puzzled. “No… I was… Yes… yes… China. That’s right.”

“Me, Sarah Jane, you…” Donna said. “It must be connected to The Doctor. Maybe they made a mistake with Gwen. Perhaps it was Jack they wanted, really.”

“It’s a trap… for The Doctor?” Gwen guessed. “They know he would come for you all.”

“No,” Martha answered in a very cool, unconcerned voice. “It is information. They need to know about Methuselah. They want Methuselah. You are the keys to Methuselah.”

“Methuselah?” Sarah Jane looked puzzled. “What’s that?”

Donna looked even blanker. Gwen shrugged. It meant nothing to her, either.

“Never heard of it.”

“What is Methuselah?” Maria asked The Doctor as she watched him pilot the TARDIS. “What’s it all about?”

“Wait,” he said as the TARDIS engines whined and huffed into a materialisation. The pattern of the vortex on the viewscreen resolved into Roald Dahl Plas in Cardiff’s Bay Area. A figure in a long military coat turned and ran towards it. The Doctor nodded to Clyde, who opened the door for Captain Jack Harkness.

“Hi, kids,” he said brightly, accepting a hug from Maria. “Doc… good to see you. Pity it couldn’t just be for a quiet lunch in a little bayside bistro I know.”

The Doctor grinned good naturedly, then both got serious.

“So… Methuselah….” Jack said in a very different tone.

“He was about to explain to us what that’s all about,” Maria said.

“Was he?” Jack was concerned. “That’s heavy stuff for kids, even these kids.”

“Sarah Jane is missing because of it. They have a right to know,” The Doctor insisted. He looked at the youngsters. “The name – Methuselah – do you know where it comes from?”

Maria and Clyde had a vague idea about it. Luke, of course, had the textbook answer.

“From the Book of Genesis, in the Old Testament of the Bible. A man who lived a very long life because God decreed he should.”

“Spot on,” The Doctor said. “Methuselah in this context is the codename for a formula – a chemical formula - which would reformat a Human being’s DNA so that their lifespan would be exponentially increased. Methuselah lived to nine hundred sixty and nine according to one translation of the Christian Bible. The formula that was developed would allow a Human – a man – or woman – to live as long as that.”

“That’s… wow….” Clyde was impressed.

“It’s remarkable,” Luke added.

“It’s wonderful,” Maria said. “People wouldn’t have to die. They wouldn’t be missed by their families. My gran… she wouldn’t have died last month.”

“Yes, she would,” Jack told her in a gentle, understanding tone. “Sorry, hun. But if Methuselah was allowed to develop your gran wouldn’t get a sniff of it. Long life would be for those who could afford to pay – and pay big money. It would be the ultimate luxury for the super rich.”

“He’s right,” The Doctor confirmed. “Except I’m not even sure it would be used for that. I rather think the one’s responsible are interested in prolonging their own lives in order to give themselves ultimate power over ‘mortals’. Imagine… if Hitler or Mussolini were still alive and still able to wield power over humanity.”

“Course,” Clyde said. “These people must already be rich. They could make those androids. You don’t do that in the back bedroom with spare parts from Maplins. They want more than just money.”

“But why is mum involved?” Luke asked. “And Donna and Jack’s friend.”

“Methuselah was deemed to be too dangerous to be left in one place. The formula was split into three parts. U.N.I.T. had one, locked in a top level file. Torchwood had another, similarly protected. The third is buried in the deep core memory of my TARDIS, in a file that only I could open, and never would.”

“So the androids were sent to get the three parts.”

“Fat chance,” Jack scoffed. “Gwen would never have access to that file. It’s in a double-deadlocked and timelocked vault in the Torchwood archive. Even I couldn’t access it. Not that I would need to.”

“Somebody didn’t do their homework, then?” Clyde pointed out. “If they thought that sending their androids into Torchwood and the TARDIS, and pretending to be Sarah Jane to get to U.N.I.T., then they really were stupid.”

“But if they’ve got our girls as hostages,” Jack pointed out. “Then they have a built in plan B. Good old fashioned blackmail.”

He looked at The Doctor, whose face betrayed the same dreadful thought. Donna and Sarah Jane were both precious to him. Jack cared about Gwen.

Would they give up Methuselah for the lives of their friends?

Luke looked at both men and bit his lip anxiously.

Would Jack and The Doctor give up Methuselah for the life of his mum?

Sarah Jane, Donna and Gwen looked at Martha curiously.

“What are you talking about?” Donna asked her. “What the heck is Methuselah when it’s at home and why would we know about it?”

“You are the confidants of those who know. The Doctor, Jack Harkness, Brigadier Lethbridge Stewart. You have access to the computer systems where the formula is stored. You will give up that information…”

“Martha…” Sarah Jane stared at her. “What are you talking about? It sounds as if you’re on their side. I thought…”

Sarah Jane stopped talking. She looked down. Gwen had put her coat on the floor, to make sitting more comfortable. Martha had walked over it. One of the plastic buttons was crushed almost to powder and there was a deep footprint in the fabric as if from something incredibly heavy.

Sarah Jane lunged towards Martha’s face, gripping it in her fingers. She pulled, and the face came off. In her hands, it felt like plastic. Beneath the face were two eyeballs that swivelled menacingly and a lot of diodes and mechanical pieces that made the face move. The android gave an exasperated snarl, still in Martha’s voice and raised a hand to swipe at Sarah Jane. She ducked, and as she did, Gwen and Donna got over their shock and came to her aid. The android was strong, but two women who both knew how to ‘put the boot in’ overpowered it. The android fell forward. There was a smashing sound from inside the exposed face. It twitched several times and was still. Sarah Jane rolled it over and pulled the blouse open. She pressed at the fake Martha’s stomach for a few seconds and a panel sprang open. She pulled out several computer chips.

“Just to be on the safe side,” she said. “The core server unit is deactivated.”

“But what….” Donna asked. In the heat of the moment she acted on instinct but now she had time to look at the android she shivered with fear. “It looked like Martha. It sounded like her.”

“Yes,” Sarah Jane said. “Except it didn’t know she was in China. Which makes me think she’s actually safe and well, there. Oh, dear…”

“What?”

“Do you think there are androids of us out there? Oh, Luke….”

“We have definitely got to get out of here,” Gwen said. “Is there anything in this android that could help?”

“But if you can’t give them the formula, because Jack doesn’t know how to open his part of it, then they might kill mum,” Luke protested.

“Not if we rescue them first,” The Doctor answered. “Which is why we have K9 along. The best tracker dog in the universe. Maria, that memory chip you took from the Sarah Jane android…” He held out his hand and she passed him the chip. K9 whirred forward and sat patiently as The Doctor opened up his side panel and inserted the chip.

“I tried this before,” he said. “With the one from the Donna android, but it fried in the TARDIS console. Too strong for it. K9 was designed to be compatible with different systems.” He closed the panel and patted K9 on the head. His ears waggled in response, then he whirred gently. His eyelights flickered.

“He’s picking up bad habits from Mr Smith,” The Doctor observed. “He used to be able to compute without a light show!”

“Master-Doctor,” K9 said. “The chip is still transmitting. Also I am picking up two similar transmissions. One is coming from Cardiff. I surmise that it is contained in the android at Torchwood. The other is coming from just off the south coast of England. The two signals are transmitting to the point of original of the third signal.”

“Just what I needed,” The Doctor answered him as he turned and programmed the TARDIS to follow the signals. “Very good dog, K9.” He turned to his communications panel and sent a transmission of his own, before turning to look at his young friends. “Luke, we’re on our way. You’ll be with your mum, soon. I promise.”

“Just off the south coast?” Jack looked at his watch. “At most, Gwen has been missing since first thing this morning. Luke didn’t notice anything wrong with Sarah Jane until this morning. How long was Donna acting odd?”

“I spotted the fake almost as soon as she came back on board from visiting her mum,” The Doctor answered. “I’m thinking that the ones responsible had access to some form of transmat technology, too.”

“Androids AND transmat,” Maria said. “Who has that sort of technology? Are we talking aliens here?”

“No,” Luke said out of the blue. “Thinktank.”

“What?” Maria and Clyde looked at him curiously. Jack and The Doctor looked impressed.

“Mum told us about them, remember,” Luke continued. “The people who designed the robot with living metal in the 1970s. The android skin… it’s sort of the same technology. And she said, when U.N.I.T. went into Thinktank, after they arrested them all for trying to take over the world, there was all sorts of stuff being developed.”

“Yeah, that’s right,” Jack said. “Back then, U.N.I.T. passed a lot of the Thinktank stuff on to Torchwood. We never got the transmat to work, though. And if we had, the Doc would have come along and took it off me. He doesn’t like me zapping about unchecked.”

The Doctor gave Jack a look that wasn’t lost on anyone.

“The Methuselah project was also developed in theory by a Thinktank scientist,” The Doctor added. “It didn’t work because it was just that – theory. It couldn’t work until Humans discovered an element that was missing from the periodic table. But that element WAS discovered in 2008. The university of Jerusalem provisionally named it Unbibium. Methuselah is possible, now. But it still can’t EVER be used. And we won’t be held to ransom over it.”

The Doctor smiled widely as he hit the materialisation switch and the TARDIS swayed and bumped and the Time Rotor wheezed. The viewscreen again changed from the vortex to a dark, hardy lit room. Luke gave a cry of delight, though, as he saw Sarah Jane looking back and smiling widely. He ran to the door and out of the TARDIS. The Doctor followed him. He turned and grinned as he saw his police box materialised straight through the metal wall of the locked room.

“No,” Donna protested. “No, I refuse to be just RESCUED by you like a damsel in distress. Another ten minutes, and we’d have worked it out. We were going to get out.”

“Well, ok,” The Doctor answered. “I’ll leave you to it.”

“No, you won’t!” She grabbed hold of him and hugged him. “I knew you’d come.”

Jack ran to hug Gwen, who didn’t make any protest about being rescued by him. Then The Doctor gently suggested they all got into the TARDIS. He glanced at the android Martha as he stepped back, and the first thing he did once he was in the TARDIS was make a long distance phone call.

“Martha is fine. She knows nothing about all this,” he confirmed. “She says hello to everyone.”

“Hello, to her, too,” Sarah Jane answered. “Doctor, do you have any idea what all this is about? Where were we?”

“On a boat, anchored off Devon,” The Doctor replied. “Hold on.” He pressed buttons on different parts of the TARDIS and they all felt movement, though the time rotor stayed still. Then The Doctor opened the door. Sarah Jane and Luke stepped near the edge. So did Donna. The others looked on the viewscreen.

The TARDIS was in mid-air over the sea. There was a boat below them, with men furiously hauling the anchor up. But they were too late. The Royal Navy was descending on them in full force, as well as the Coastguard in two helicopters.

“U.N.I.T. aren’t the only military I have connections with,” The Doctor said. “I called the navy. Anyone on board that boat will be arrested for piracy on the high seas.”

“You’d better tell the navy to give me my sonic screwdriver back,” Sarah Jane said. “And my watch. And we’re all missing our mobile phones.”

“I’m sure we can sort that out. Meantime, we’re off the coast of Devon, and it’s tea time. Let’s see if we can find a nice café for a good old fashioned Devon tea?”

They made for a very strange party, but a seafront café in Torbay provided them with tea, sandwiches and Devon cream scones under umbrellas outside, where K9 was able to hunker down under the table when the waitress wasn’t looking. In the middle of it all, The Doctor had a phone call.

“Everyone on the boat is in Royal Navy custody,” he said. “Along with some interesting technology that U.N.I.T. will be taking charge of. No, Jack, you’re not having the transmat. The only thing is, the people they’ve arrested just seem to be sailors and guards – general henchmen. There was no sign of the brains behind the operation. He or she got clean away.”

“That’s not good,” Maria commented. “They might come after Sarah Jane again.”

“There will be a thorough investigation,” The Doctor assured her. “U.N.I.T. and Torchwood will be working together on it, as well as MI5, since the attempt to get hold of Methuselah does qualify as an act of treason. Whoever it is, they’ll be found. So you can all relax, and Donna and me can get off once we’ve dropped you home. I was going to show her the Medusa Cascade. Fascinating place. Didn’t I take you there, once, Sarah?”

“No, I don’t think so,” Sarah Jane answered. “But we did plenty of other stuff. So I’m not jealous. This Methuselah project – it’s safe now?”

“Safe as houses,” The Doctor assured her.

“I hope so,” Maria said. “When they found out how dangerous it was, did nobody think to build a big bonfire and BURN all the formulas and notes? In the long run, it would have been safer.”

“Out of the mouths of babes,” The Doctor whispered and smiled. “You’re right, Maria. We should. When a Human first split the atom, we should have closed down the laboratory and blown it sky high. When somebody suggested that Human cloning could really work… Just because we scientists CAN, doesn’t mean we SHOULD.” He seemed to consider that idea for a little while, then he smiled and helped himself to a scone with cream. Maria did the same. So did everyone. Under the table, K9 gave his synthesised version of a satisfied sigh. All his friends, including The Doctor-Master were together. Robot dog contentment was complete.