Back on Earth, everyone had finished their Christmas dinner. They were in the living room, watching the Christmas movie playing on TV. But the Professor and Clara weren't watching it. Or focused on it. They were upset with having been abandoned by the Doctor.

Across from them, Dave – Clara's father – had his granddaughter, Ellie, on his lap and was entertaining her with a cuddly penguin. She squealed in delight.

Belle smiled as she watched the two of them. "She loves that penguin," she said.

"It was her mother's when she was younger," Dave said, smiling at Belle. "I think Ellie might like to have it now."

The Professor looked over at them. "I think she'd like that," he said, then sighed. "I still can't believe he did it again. He left me with Rumple. Again. Not that that's a bad thing …."

"You want to be with your father," Dave said. "I get that."

Clara looked at everyone. "Come with us," she said. "Back to Storybrooke." "Storybrooke?" Linda asked. "That's an ocean away."

"So? We'll be a family. We'll be together."

"That's not a bad idea," the Professor agreed. "Look, just leave everything to me."

Gran frowned as she looked down at her Christmas cracker. "These crackers are rubbish."

"Hey, I brought them," Linda retorted.

"I know."

"They're classy."

"But they don't have jokes."

"Exactly."

"They've got poems."

"They're more dramatic crackers."

"I like the jokes."

Coming out of the kitchen, Mr Gold looked at everyone before putting his phone back into his coat pocket. "That was Storybrooke. There was no answer. The place is a dead end. Like it's not even there."

"So we're stuck here?" Clara asked, looking up.

"It appears so. Until Snow and Charming cast their curse that brings everyone back to this land."

Dave looked at them. "You're more than welcome to stay here."

Clara smiled. "Thanks, Dad," she said before hearing something from outside. The TARDIS engines. They all heard it.

The Professor got up from his spot on the sofa and rushed into the kitchen. Clara and Mr Gold followed him. They could see the TARDIS standing outside the flats.

"What's wrong?" Dave asked as he gave Ellie to Belle.

The Professor, Clara and Mr Gold ran back into the living room. "Everyone, just stay put!" Clara told them, taking a cracker from the table.

"We'll be back soon … I'll be back soon," the Professor said as Mr Gold waved his hand, engulfing himself, the Professor, Clara and Belle in purple smoke – poofing them in front of the TARDIS. They entered the TARDIS, but they were all startled to find Tasha Lem at the controls.

"You can fly the TARDIS, dearie?" Mr Gold asked.

"Flying the TARDIS was always easy," replied Tasha. "It was flying the Doctor I never quite mastered."

"He can be stubborn at times," the Professor said.

"What's happened to him?" Clara asked, but Tasha didn't answer her. Instead, she only gazed intensely at the four of them.

The TARDIS arrived back in war-torn Christmas. An explosion to the left made Clara jump, and the Professor reached out to hold her hand. He gave it a slight squeeze. "We'll be alright."

"What are we supposed to do, dearie?" Mr Gold asked Tasha.

"He shouldn't die alone," Tasha said. "Go to him."

As Tasha walked away, the four of them walked down the street amongst panicked townspeople, and they climbed the steps to the church. They entered the church and slowly descended the stairs to the crypt, with its picture covered walls. They didn't know what they would find. But, they smiled as they saw the Doctor repair a wooden toy.

"Barnable?" the Doctor asked, not looking up from his work.

"No. Just us," the Professor said. "Your family." The Doctor, now even more ancient, drops the wooden dog. He turned around and looked over at them. "Hell, Dad," the Professor continued.

The Doctor peeled his glasses off his deeply lined face. "Were you always so young?"

"That was you," Clara said as the Doctor reached out to them and drew them closer. "Merry Christmas," she whispered.

"Merry Christmas," the Doctor repeated.

Clara offered the cracker to the Doctor and knelt in front of him. But the Doctor was too weak to pull it.

"Allow me," Mr Gold said, walking around the back of the Doctor's rocking chair. "You were there for me when I needed you, Doctor. Now it's time to repay the favour." He placed his hand on top of the Doctor's and helped him pull the cracker and open it.

"Is there a joke?" the Doctor asked as he watched Clara look at the contents that had fallen out. Then, he sat back, smiling in anticipation.

"Extract from Thoughts on a Clock, by Eric Ritchie Junior," Clara read.

"Is it a knock-knock one?" The Doctor asked. "Those are the best."

"I think it's a poem," the Professor answered. "Well, read it. Go on," the Doctor told them.

" 'And now it's time for one last bow'," Clara read. "'Like all you other-selves. Eleven's hour is over now. The clock is striking twelve's.'"

"I don't get it," the Doctor stated when he was interrupted by a booming voice overhead.

"Doctor!" came a Dalek outside. "The Doctor will be brought! The Daleks demand the Doctor!"

A young man ran down the steps to the crypt. "They're here," he said. "The Daleks, we can't stop them. They want you."

The Doctor looked at him. "All right, Barnable. Are you Barnable?"

"No, Doctor," the man said.

"It's okay, Barnable, don't worry. I have got a plan. Off you pop." The young boy ran back the stairs. "I haven't got a plan, but people love it when I say that." He reached for his stick.

"Dad, what are you going to do?" the Professor asked.

"I don't know," groaned the Doctor as he strained to get up. "Talk very fast, hope something good happens, take the credit. That is generally how it works."

"Doctor…" Mr Gold began.

"Not this time, though. This is it." "No!" Clara told him.

"Yes," the Doctor replied. "We saw the future, Clara. This is how it ends."

"Then change it," Mr Gold told him as he stepped closer to him. "Do not let fate tell you what to do. Just say no."

"Like what Tasha said," Clara added. "Change the future!"

"I could have once," the Doctor said, slowly approaching the stairs. "When there were Time Lords. Not anymore. You all need to stay here. Promise me that you will."

"Why? We have Rumplestiltskin on our side," the Professor said. "He will protect us."

"It's what I have always done," the Doctor told his son. "Keeping you safe. One last victory for me. Allow me that. Give me that." He leaned in and hugged him. One last time. "My son. The future of our race. Thank you, and goodbye. To all of you." He looked at them before walking away, up the stairs to the clock tower. "Trouble with Daleks is they take so long to say anything. Probably die of boredom before they shoot me."

"Give me my dagger," Mr Gold said to the Professor. "Why?" the Professor said.

"You will see soon enough."

The Professor took the dagger out from his coat pocket and gave it to Mr Gold, who then walked over to the glowing crack in the wall. "I don't know if you know who I am, dearie, but you will listen to me," he said into the crack, placing the tip of his dagger on the bottom of the crack. "The Doctor is my oldest friend. You will help him. Help him change the future. Do something. Anything." Mr Gold took a deep breath. "You have been asking the wrong question. Take it from someone who deals with names. His name is the Doctor. It is all the name that he will ever need. It is everything that you need to know about him. And if you do know who I am, dearie, then you know who I am. And if we ever get the chance to meet, the chances of you surviving our little encounter will be pretty slim." Mr Gold got up again, and he began to walk away from the wall. When he did, the crack closed up. "I did my best."

They all left the church and were confronted by a crowd of townspeople. They all looked up as they saw the Doctor on the church's balcony and a Dalek mothership overhead them.

"Sorry, I'm a bit slow," the Doctor told the Daleks. "I may not be at my best right now."

"You are dying, Doctor," the Dalek said from the ship.

"Yes, I'm dying. You've been trying to kill me for centuries, and here I am, dying of old age. If you want something done, do it yourself."

"You will die, and the Time Lords will never return."

"You still can't work up the courage to shoot me, can you? You're still worried I've got something up my sleeve!" The Doctor shook his stick angrily at the ship from his spot on the seat on the balcony. "Well, you knock yourselves out, boys. I've got nothing this time."

A Dalek craft flew through the town, shooting energy beams at the ground. The Doctor puffed out his cheeks and shook his head in despair. He felt worthless. He couldn't do anything to save the town anymore. But, in the sky above him, the crack appeared again. It split the night sky in two, catching the Doctor's gaze. The Doctor watched it with a frown as the Dalek blasts destroyed buildings. A golden mist drifted through the opening of the crack. Strands of the plasma soon flowed into the Doctor's mouth. His eyes widened in surprise as he swallowed the energy from another universe. His fingers and hands began to glow.

"You will die now, Doctor," the Dalek on the ship boomed. "This is the end of you."

The crack in the sky closed, and the Doctor stared at his hands. He felt stronger now.

"The rules of regeneration are known. You have expended all your lives," the Dalek continued.

The Doctor stood up now. "Sorry, what did you say? Did you mention the rules? Now, listen! Bit of advice. Tell me the truth if you think you know it. Lay down the law if you're feeling brave. But Daleks never, ever tell me the rules!"

"Emergency! Emergency!" the Dalek boomed as the clock tower began to chime. "The Doctor is regenerating! The Doctor is regenerating!"

"Oh, look at this—regeneration number 13. We're breaking some serious science here, boys. I tell you what. It's going to be a whopper! Ha-ha!" "Exterminate! Exterminate the Doctor."

"You think you can stop me now, Daleks?" the Doctor asked, throwing away his walking stick. "If you want my life …" He laughed in glee. " … Come and get it!" The Doctor windmilled his right arm, and golden energy streamed skyward from his hand, taking out a golden craft.

The Professor looked at the inhabitants of Christmas. "Get inside!" he told them. "Get off the streets!"

Clara joined him. "Get inside, quick, quick!" she said as she and the Professor marshalled the people inside the buildings.

Energy streamed from the Doctor's other arm, and another Dalek craft is brought down. The Doctor laughed. "Love from Gallifrey, boys!" he yelled out. Golden fire sprouted from the Doctor's head and ripped into the Dalek mothership above him. Energy erupted from the church tower, sweeping away Daleks on the ground and rocking the TARDIS.