Note: At the moment I'm writing this I have only seen Merlin Season 1 + 2 and so you have to excuse me if something out of Season 3 contradicts something I write here.
Note2: As always my thanks go out to Inachis, without her you wouldn't read my stuff :)
All looked around and stared at Xander. Suddenly both Willow and Buffy began to giggle.
Xander looked at his two friends in confusion and then looked down on himself to see if there was something funny on him. Not finding anything he looked up again and asked, "What?"
As the two girls started to giggle even more Xander looked at Giles, who he regarded as more of a father than his own, and asked, "Giles...why are Ms. Slayer and Ms. Hacker in a giggle fest?"
Giles who smiled himself a bit took a deep breath and answered, "My guess would be because of your question ‘Did I miss something?' to which the answer would be a certain yes."
At seeing the questions on Xander's face the two girls started to hiccup from all the giggling.
After the girls calmed down a bit, Giles quickly explained what had happened so far to Xander.
Xander looked at Giles and Merlin for a moment and then said. "Uther and Merlin? Wow that's awesome and Merlin? I always loved your duel with Madam Mim. That was just funny to watch."
While Merlin and Buffy looked a bit confused about that comment, Giles groaned and Willow started to giggle again. Merlin looked at the young man for a moment and in a comic you would have seen a big question mark above his head for sure, finally he asked, "Madam Mim?" which made Willow giggle even more.
Rupert or Uther, whatever you prefer, quickly explained to Merlin what Xander was talking about, to which Merlin just shook his head with an amused smile. He then turned to the young man who had just joined them and started to look at him quite intensely. As his eyes stared to glow Xander soon became quite nervous and asked, "Uhh Giles, what is he doing? It looks like he is studying me."
Before Giles could answer Merlin seemed to join them in this world again and replied, "Indeed young man, I was studying you and your aura. I came here to search for someone and it looks like I found you."
"You were looking for me? Why?" Xander asked surprised.
"I was looking for you, young Alexander, because," here he paused a bit and then continued after taking a deep breath, "you are the last Pendragon."
In the silence that descended at those words you could have heard the fall of a pin, but that silence was shattered only a moment later by the yell of "What???" out of four shocked throats.
Smiling, Merlin said, "Was I mumbling?" and after looking around he cleared his throat and said loud and clearly. "You Alexander are the last Pendragon or the great, great, great whatever grandson of Uther Pendragon, who you currently know under the name Rupert Giles."
"He is my great grandson? How is that possible? Arthur never had children before he died," Giles said and at the same time Xander said, "The G-Man is my grandfather?" While Buffy just repeated the formerly uttered "What?" and Willow said. "My Xander is of Arthur Pendragon's bloodline? I don't believe it." And as she remembered who Giles truly is, she stuttered, "Sorry Giles, I meant to say your bloodline."
Giles closed his eyes for a moment, took a deep breath and then said, "Merlin, could you explain that? My son died childless and I never had any other children."
"Maybe we should sit down first?" Merlin said and after all nodded and sat down at the huge table in the middle of the library they usually used for research, Merlin's eyes glowed again for the fraction of a second, causing Giles' tea kettle and several cups to fly out of his office.
As the children all stared at him with open jaws and Giles just shook his head and quietly mumbled, "Showoff", Merlin poured them all a cup of tea. After he had sipped at his, he finally said, "As far as we all knew, at least at that time, you are right and Arthur died childless. As always though, history turns out to having a ‘BUT' in there somewhere and our ‘BUT' at that time was named Gwen."
At this Giles looked up and said, "Morgana's servant?"
"Indeed My lord," Merlin replied and then continued. "After Morgana betrayed us all, you had Gwen banished from Camelot because she was your wards servant. As always, you ignored everything Arthur tried to tell you and so she left Camelot. I helped her to find our friend Lancelot and after a while their friendship and attraction let to more and the two then lived quite happily together. Gwen had two children."
Giles looked thoughtfully at Merlin and then said, "Quite interesting, but what exactly has that to do with my son?"
"Quite simple really, Sir. Gwen and Lancelot only became a pair after her first son was a little over six months old. What Arthur tried to tell you was that he and Gwen loved each other, but as you so often did at that time, you brushed him off and none of us knew that Gwen was already pregnant when she left the castle," Merlin explained with a pained expression while Giles buried his head in his head.
"Why have you never told us?" Giles asked a bit later.
"Because I didn't know then myself. I visited them whenever my duties in the castle allowed it, which wasn't often, and so I thought that the child was Lancelot's son. I only learned the truth much later and by that time the dragon had already killed you, as we all thought, and Arthur had died on the battlefield."
Giles sat shocked in his chair and after a few moments he took his cup of tea with sharking hands and drank a sip out of it. Then he looked at Merlin for quite a while, unsure of what to say. After a few moments of silence Xander asked, "So what happened then? Why isn't the Pendragon line still sitting in the land of tweet?"
Merlin smiled at that and replied, "After Arthur died chaos came over the land, a time that is now called the Dark Ages. Minor nobles and kings fought over everything and no one was safe. As I said, I wandered the land for quite a while and so I only came back to Gwen and her family as her daughter celebrated her 15th birthday."
(Flashback, a few hundred years earlier)
The young man in rather torn traveling clothes, who had just entered the small village, looked to the casual observer rather tired, but that would have been a gross understatement. He walked to the middle of the village where he halted and then looked around. He seemed to orient himself as if he hadn't been here for quite a while, which in fact was the truth. The last time he was in this village was over 12 years ago and he hoped the family he wanted to see still lived here. He looked around a bit more and seemed to be trying to remember where to go, but if someone would have watched him more closely they would have seen his eyes flash golden for a moment. After that he strode out certainly to the north end of the village, where he knocked at the wooden door of a cottage.
It only took a few moments until the door was opened by a young girl, no he had to correct himself, by a young woman not older than 15 summers. "Yes?" the young woman asked with a bit suspicion of the stranger she had never seen before in her voice. Nowadays strangers were seldom good news.
The stranger smiled at the young woman and said, "Happy birthday Eliza. I'm here to celebrate your 15th birthday with you and your family. Is Gwen or Lancelot nearby?"
The girl looked a bit startled at the stranger who seemed to know her parents and that today was her birthday and then nodded. "Yes, they a both here," she replied.
"Good, would you tell them an old friend from better times is here to see them and their children? I'll wait here," the man said.
The girl who the man had called Eliza quickly closed the door again and the yell of, "Mother, Father" could even be heard outside.
The man smiled a bit more happiness than he had looked to have before and waited. A few moments later the door was opened again by an older, but still beautiful looking Gwen. She started to say, "Yes how can..." but as she looked at the face of the stranger, she went quite and looked surprised. "Merlin?" she said astonished.
"It's me," the man said. "Can I come in? I even have a gift for the birthday child."
Still shocked Gwen ushered her old friend in and quickly closed the door behind him. "Merlin...how?"
He looked at her questioningly and asked, "What how?"
"How can you still look like the last time we saw each other? You don't look one year older than when you left for your wanderings 12 years ago," she asked her friend out of old times.
Merlin shrugged. "I really have no clue, Gwen. If I had to guess, I stopped aging the moment Arthur fell, but I have no clue why. After all, I failed my duty that terrible day," he said solemnly, but he still noted that Gwen kinda blanched at that and so he asked, "What is it, Gwen?"
Gwen took a deep breath and replied, "I guess you will see as soon as Lance and my son come back in an hour."
Merlin nodded and let it be for the moment. Instead he pulled his backpack to him and looked at Gwen's daughter. "I know you don't remember me, but as you probably have guessed from my talk with your mother, I'm an old friend of your family. The last time I saw you, you hadn't even had your third birthday yet and so for all the birthdays I missed I have a special gift for you." With that he picked the old and worn looking backpack up and gave it to her.
Eliza looked at Merlin like he was crazy, but took the backpack and said, "Thank you, sir," while thinking something about ‘crazy strangers' or so.
Seeing her look Merlin had to smile and said, "Ahh Eliza, don't call me crazy just yet, but check it out first."
Not wanting to anger the stranger the girl did as he asked and opened the pack. She looked into it and took out a few apples and a wineskin. After that she looked up at the stranger, who at that moment said, "And now think about a beautiful hand mirror and reach into the pack again." She shook her head, but did as the stranger asked and suddenly her eyes opened in surprise as her hand suddenly felt something in the pack. She closed her hand around it and as she pulled it out, she could see a beautiful silver hand mirror decorated with several emeralds and rubies. She couldn't help herself and a delighted "Oh" came out of her mouth.
Gwen looked in astonishment at the mirror, the pack, her daughter and then at Merlin. "Merlin?" she just said.
Merlin looked at her with his to her well known smirk and explained to both of them, "Ah, you know the backpack is something I came up with while I was traveling and got bored. You can put anything in it that fits trough the opening and hide it with a thought and only you or someone you allow to can take it out again. Awesome, isn't it?"
Before Gwen or her daughter could say anything they heard the door open and they heard a happy sounding voice yelling, "Merlin" and with that they saw Lancelot enter together with his son. At least Merlin thought so until he saw the young man. "That cannot be," he mumbled in astonishment. "What?" he asked looking at all of them.
"That's what I wanted you to see for yourself Merlin. My son Arthuros," Gwen said.
"He resembles Arthur like...like...," Merlin mumbled.
"Like a son," Gwen said quietly.
Merlin blinked a bit and came back into the now and then and looked at the faces of the four people who were listening to him. "And that was how I found out the line of the Pendragon survived," he concluded.
The four were speechless until Xander found his voice again, "But that still hasn't answered my question from earlier."
"Indeed, it hasn't. The times then weren't right for a bastard child of Arthur to come forward and claim the throne. He would have been assassinated by the nobles and other kings faster than he could have sat down on the throne. So I used magic to hide the Pendragon line until one of the descendants earned the privilege and then was named a knight. This has brought me here and to you now," Merlin explained.
"But why?" Buffy asked.
"You remember your stay in the hospital when you had the flu?" Xander asked and as Buffy nodded, he continued with a light blush on his face. "Angelus wanted to get to you then and when I used a bluff to drive him away, he named me your White Knight."
"You did what?" Buffy asked.
"I...I didn't let him pass to get to you and after he tried to mock me, he left," Xander explained.
"Xander...that... that was...," Willow muttered, not finding the right words.
"Heroic and worthy of a knight?" Merlin offered up and smiled as both girls glared at him.
Finally it seemed that Giles has found his voice again as well. "I had a grandson?" he asked no one in particular. Then he stood up and engulfed Xander in a grandfatherly hug.
A few moments later Giles let the surprised Xander go again, who then after a few moments he used to come over his surprise by being hugged by Giles, asked, "OK, that's all very interesting, but what now?"
Merlin smirked and said, "Now young Pendragon, I and Uther will start your training to prepare you."
Xander looked at the wizard in and had to ask, "Prepare me? Prepare me for what?"
"For the things coming for you," Merlin replied, which told Xander not really much.