He was a Space Marine, damnit! Supposed to destroy the alien, the mutant, the heretic.
And now, he was following an alien princess to her private quarters. But not an regular alien: those ponies turned mankind's experiences upside down. Even all of them he had met until now combined were not half as spiteful as the average Eldar or Tau.

They arrived at Luna's room soon, not too far away from her sister's.
It was as cozy as Celestia's, although in a different way, and darker in color. The ceiling was covered with a night-themed fresco and in its center was a huge glass dome. There was something particular that attracted Antonius' attention: The whole room had some Gothic influences that reminded him of the Imperium.

"And? What do you think of my quarters?" Luna asked.

"A nice place to live," Antonius answered.

She was about to sit down on a huge carpet and said:

"Thank you, I hoped you... OW!"

She stood up again and looked at her flank where Antonius had hit her with the blunt side of his chainsword.
Had he injured her? That would be quite unfavorable. He had to do something.

"Have I hurt you?" he asked.

"Oh, I'm sure it's nothing," she said as she moved her hind leg in small circles.

"Let's play it safe. I'm not an Apothecarius, but I know a thing or two about first aid. You need to take off your armor, though."

"Of course, I did not plan to keep it on the whole night, anyway."

Hmm, why did that sound a little weird? Nonsense.

Luna got out of her armor and laid down for Antonius to have a look at her flank, where the sword had hit her and where her cutie-mark was.
He couldn't see anything, the fur was too dense. So, he carefully stroked the fur aside to take a look at the skin underneath. Still nothing.

"Hmm... I can't see anything. You could perhaps..."

He stopped talking when he noticed a very strange fact:
He had stroked aside her fur, but her cutie-mark was still in place. How could that be?
He stroked the fur again and watched carefully. The hairs instantly changed color to keep the cutie-mark in place! It was strangely fascinating. He repeated this experiment with the same result: the hairs immediately changed color.
Those marks really were 'magical symbols', just as Apple Bloom had told him when they first had met.

Antonius froze when he finally realized what he was doing. That was not exactly an acceptable way of treating a leader of an ally.
He quickly pulled his hand back and turned towards Luna.

"Sorry," he said,
"but I am not familiar with this whole cutie-mark system. It is... intriguing."

She just smiled:

"No problem, I'm proud of my cutie-mark. I see your interest as an honor.
I guess we are the first species you encountered with marks like these?"

"If you ignore the marks of Chaos, yes."

"Not a very charming comparison."

Yes, she was definitely right with that.

"I did not mean to insult you," Antonius assured her.

"Don't worry, you didn't."

Good, accidentally hurting her was unfavorable enough - even if he couldn't see an injury.
Wait a moment, that was not the only attack that had hit her...

"What about your chest, Luna?" he asked.

"My chest?"

"The chest I slammed into a few minutes ago. When the sword thrust has injured you, your chest could also have been affected."

"Oh, I think my chest is fine, but it would probably be better if you could you have a look."

Antonius did her the favor and confirmed her suspicion:

"You were right. No sign of an injury and the ribcage is also intact.
After seeing this, I am honestly not sure that my attack caused the pain you feel."

"Well, I think it is a strain. It was an exhausting fight and I am admittedly a bit out of practice."

She lighted her horn and her flank was surrounded by a dark blue aura. When the light faded, she said:

"So, I'm fine again."

Antonius raised an eyebrow:

"Healing-magic?"

"Exactly."

"Why haven't you done this in the first place?"

"You should know an injury before using healing-magic, as it is a quite complicated kind of magic. You can't just pour magic into a wound, strain or whatever and expect it to immediately heal. You must direct the magic, tell it what to do at any time."

Oh, that was interesting. And it was the reason why Luna had been unsure if healing-magic could help his Primarch.
After a short silence, Luna continued:

"If you don't mind, we could talk a little more."

They sat down on the carpet between some cushions and continued the conversation they had had with Celestia.
Shortly afterwards, Luna yawned.

"Oh, I'm sorry, Antonius, but I barely got any sleep the last two days.
Well, there is still time before the nightly patrol starts, so we could take a nap. If you wouldn't mind staying here, I will show you your room once we are back. Now, it's barely worth the effort for this short amount of time."

Antonius nodded and Luna continued:

"As my guest, feel free to use my bed, I'll stick with the carpet."

"Thank you for your offer, but that is not necessary. Furthermore, your bed won't be able to stand the weight of my armor."

"Why don't you take it off, then?" she asked.

That topic again. This time, not too much diplomacy, just politeness.

"Since humans don't have fur, it is considered indecent to run around without clothes. You should never ask a human to take off his clothes, or in my case, armor. There is some... ambiguity."

Luna looked a bit confused now.

"You mean... THAT kind of ambiguity?"

"Correct."

"So, I accidentally put myself in the role of..."

"Don't worry, I just see it as an intercultural misunderstanding."

"Oh, yes! I would never even think of... no, that's rude...
I certainly would... no, that's not really better...
I mean..."

She sighed and continued:

"Perhaps we should stop talking and go to bed...
NO! I did not mean it THAT way!"

She buried her head in the cushions and mumbled:

"This is so embarrassing..."

Antonius could barely keep himself from laughing. Luna was not just the Princess of the Night, she was also the queen of accidental ambiguity!

The mere thought of a human-pony relationship was equally disgusting and ridiculous.
They were animals, for Emperor's sake!!!
...
Except for the fact that they weren't.
They were fully intelligent, sapient and sentient creatures, they just looked like animals.
But they still were aliens, and even if they were friendly, that kind of relationship with a nonhuman was absolutely unthinkable.
Cooperation? Yes, if necessary.
Friendship? Weird enough, but in their case, tolerable and even justified.
More? No. Definitely not.

Luna turned her head a bit and one of her eyes peeked out of the cushions and looked at him. He smiled down at her.
Yes, she was kind of adorable.
Crap. He really had thought that, hadn't he? Certainly a ramification of his humanity.

Now, he finally realized the meaning of Celestia's comment, and he was not very comfortable with it.
Not at all. What a weird situation... What a weird kind of humor... at least Luna's reactions had been quite funny. He would simply ignore the rest.

"Oh, well, I think I'll go to bed now... in my bed... alone," Luna said as she stood up and went through a door into another room.

Antonius found a spot not too far from neither too close to her bed and sat down there, his back against the wall.
A few minutes later, she came back, took off her necklace, tiara and shoes and crawled into her bed.

"Goodnight, Antonius," she said,
"would you mind meeting me in a dream again?"

"Not at all, Luna, but can you properly regenerate while doing your dream-walking?"

"Not as much as when I'm completely asleep, but it will do."

"Then, goodnight. See you in a moment."

Luna smiled, closed her eyes and was soon asleep.
Antonius also started to relax. This place was safe, he could take a nap. He had the feeling that he needed one.

Luna did not have to wait long for Antonius to arrive in the dreamscape.
She had created the same environment as when she first had visited his dreams, but she did not plan to stay here the whole time. She wanted to get to know more about him, so she greeted him:

"Hello, Antonius! Is there anything special you want to see or may I ask a favor of you?"

"What do you want?" he asked.

"You told us how you became a Space Marine. Now, I'm curious. Could you show me some of your memories in that regard?"

"Okay, Luna. I think I'll show you my 'final exam'."

Something about his intonation and the small smile told Luna that this would be anything but an normal exam, but it would certainly be interesting. She used her abilities and read the memory he thought about, then, she recreated it.

The environment vanished and was replaced by a different one. She knew where they were. She had seen those gigantic buildings before. They were in the Fortress of Hera, but this time, they were inside, high above the ground on some kind of parade ground. Next to a wall, a group of young humans was standing in rank and file in the sunlight. Luna recognized one of them.

"Is that you?" she asked.

"Yes," Antonius answered,
"shortly before becoming an Neophyte."

She looked at the young Antonius. Compared to the later Antonius, this human looked fragile, but there was something about his eyes - the same determination she knew from her friend.
Luna took a look at the other humans on the parade ground. There were a few Space Marines in their blue armors, as well as another Space Marine in a white armor, only his pauldron bore the blue of his chapter.

"An Apothecarius, about to tell us the results of the tests," Antonius - the real one - explained.

While this Apothecarius was reading from some kind of... book, yet another Space Marine came into view. This one wore a strange kind of hat Luna had never seen before, and had a giant staff in one of his hands. He downright radiated authority and power.

"Antonius, who is this Space Marine with the strange hat?"

Antonius laughed.

"If you should ever meet him, don't tell him that. This hat is the Hood of Hellfire, a psychic hood, and the Space Marine is Varro Tigurius, Chief Librarian of my chapter."

"Librarian? Like Twilight Sparkle?"

"No! 'Librarian' is a title for Space Marine psykers, and I can tell you, he is an incredibly powerful one."

"So, a librarian who can use magic. That is a bit like Twilight, isn't it?"

"It is not magic! Even though Twilight's powers are quite impressive, Chief Librarian Tigurius' powers are another order of magnitude."

Tigurius came closer, and everyone snapped to attention - even more than before. He strode past the young humans, taking an appraising, yet friendly look at them. When he passed young Antonius, he slowed down for a second, then, he continued his way. He reached the end of the row and turned to a Space Marine who was standing there, whispering something to him.

"What is going on?" Luna wanted to know.

"Just wait and see," answered Antonius.

The Space Marine Tigurius had talked to walked along the row of youngsters until he was directly in front of young Antonius.

"This is your lucky day, lad. Show me what you've got!" he said to the boy.

Then he turned around and walked a few meters towards the middle of the parade ground, followed by Antonius.

Luna was flabbergasted.

"What the...? Did he just challenge you? He is kidding, isn't he?"

"Not at all," Antonius explained,
"sometimes, an Aspirant gets the chance to prove himself in a duel with a Space Marine. I had this honor."

Two other Space Marines went to the two unlike opponents and handed them swords. For the Space Marine, it was a short sword, for Antonius, it looked more like a great sword.

"This is unfair," Luna complained.

"This is a challenge," rectified Antonius.

"You don't have a chance to win!"

"This is not about winning, it's about how you fail."

Huh? That was crazy!

The Space Marine told young Antonius:

"Okay, lad. Pretend that I am an enemy of mankind. Go!"

Now, they started fighting. Luna could barely look. Young Antonius did his best, but he did not have the slightest chance against the armored hulk. Yet, he did not give up.

"You need to vary your attacks to a greater extend," the Space Marine told him,
"try to surprise me."

Young Antonius crouched and attacked his opponents legs, not unlike Luna had done when fighting the real Antonius. Similar to her attack, the Space Marine deflected it without problem.
Then, his gauntlet came down. Young Antonius tried to dodge, but he was a tad too slow. The attack grazed him, sending him to the ground. He quickly rolled out of his opponent range and came back to his feet, a bit shakily, but he stood again.

Now, he attacked. It was in vain again, but this time, the Space Marine's sword quickly came down on his right arm.
At the last possible moment, the Ultramarine twisted it and hit Antonius' right arm with the blunt side.
Luna could hear bones break and the boy let out a short scream.
His sword fell to the ground. He immediately picked the weapon up with his left hand and got into position again.

"You are crazy," muttered Luna.

"Thank you," smiled the real Antonius.

Fighting with his left hand, the boy had even less of a chance.
Another attack of the Space Marine sent him to the ground with a sick, crunching noise.
Luna knew that young Antonius was severely injured now, barely more than a beaten heap of flesh on the ground.
Yet, he tried to stand up again.

"I take it back," Luna said,
"you are not just crazy, you are downright suicidal."

The Space Marine seemed to think the same, as he told young Antonius:

"Lad, you are defeated. Stay down and surrender, it wasn't a bad performance."

Young Antonius looked up at him:

"You told me to pretend that you are an enemy of mankind. I will NEVER surrender to an enemy of mankind!"

The Space Marine seemed a bit surprised and looked at Tigurius, who simply nodded, smiling a bit, then, he turned back to his opponent, taking off his helmet:

"That's the spirit, lad! You passed the test. Consider yourself an Ultramarine."

"Thank you, my Lord."

"Apothecarius, take care of Neophyte Varus," Tigurius ordered, still smiling a bit,
"Seneca, assist him. Now that you have beaten the crap out of the boy you can also help transport him to the Apothecarion."

"Of course, Chief Librarian," Seneca answered, also with a smile on his face.

While he was helping the Apothecarius to place young Antonius on a litter, Tigurius walked along the row of young humans. Luna took a look at them. They all looked at the scene in awe.

"Aspirants," Tigurius boomed, now completely serious again,
"you all have seen this. Devotion. Determination. The iron will never to surrender, no matter how bad the odds might look.
That is one of the key features of every single Astartes. Now, you are about to become Astartes, Ultramarines!
Together with your brothers, you will be the breakwater that protects mankind from the tides of aliens, mutants and heretics!
You will never falter, never be found wanting! You will be the guardians of mankind and the harbingers of the Emperor's wrath!"

The environment started to vanish. A moment before it was gone, Luna had the impression that Tigurius was quickly taking a look at her. That was impossible, it must have been her imagination or a strange coincidence. It was just a memory, after all, she had never been really there.

Now, she and Antonius were standing in her dreamscape again.

"Wow," Luna said,
"that was an... unusual final exam."

"Yes, it was. Even for Space Marines."

"Why did Tigurius pick you for this test? He slowed down as he passed you."

"I have no idea, but Chief Librarian Tigurius is a mystery. Perhaps he has seen something in my mind, or he has foreseen something, though I can't imagine what that could have been. I'm pretty much an average Ultramarine, nothing special."

"You are the only Ultramarine in Equestria, and, according to the stories you told us, the first human in recorded history to befriend non-humans."

Antonius looked sceptical.

"I really don't think he has foreseen this."

Luna wanted to reply, but she felt that something was... wrong.

"Luna?" Antonius asked, realizing that she was concerned.

She did not answer. Instead, she used her magic to check the dreams of the ponies in the castle. She found...

"Celestia!" she shouted.

"What's up with Celestia?"

"Antonius, wake up. I need you in the real world. Now!"

Antonius immediately woke up and jumped to his feet. Luna did the same and rushed towards the door and out of her quarters, followed by him.

"Luna, what the hell is going on?" he wanted to know.

"I sensed a terrifying darkness in my sister's dreams. She has the gift of foresight, and I think she has a vision of something important - and cruel."

As if on cue, they heard a scream echoing through the hallway.
Celestia.

"Antonius, if you can be faster than me, then RUN!"

Antonius did exactly that. He overtook Luna and dashed down the corridor. He had only gone this way once, and in the opposite direction, but that was enough for his enhanced memory to guide him. He rounded a corner and Celestia's quarters were directly ahead now.
In front of the door a group of guards was standing. One of them carefully knocked at the door.

"Your majesty? Are you all right?"

Fools. Their princess was screaming in horror, and they knocked and asked 'Are you all right?'.
Ridiculous. They turned towards him as he approached:

"Mr. Varus, what are you doing..."

"What are YOU doing?" he interrupted,
"your princess obviously needs your assistance!"

Without slowing down, he smashed his pauldron into the door. It could not stand the impact and was ripped if its hinges, while being shattered at the same time.

Antonius barged into Celestia's quarters and immediately checked the room. No sign of a threat, but the princess was sitting in her bed, panting and dripping with sweat. She turned her head and looked at him. He could see fear. No matter what she had seen in her vision, it had shaken her to the very foundations.

"Celestia, what is going on? Are you all right?"

Crap. Now he had said it. Well, what else was he supposed to say ?

He came to a stop beside her bed and crouched to be more at eye level with her. She still looked at him.

"Antonius?" she asked.

"In person," he answered.

Now, Luna came running into the room.

"Sister, are you all right?"

Hmm... everyone seemed to ask that question.

"Luna!" Celestia exclaimed,
"I'm happy that you are here."

"What have you seen, sister?" asked Luna as she stepped up to her sister's bed.

Celestia cringed.

"Have you not seen it, Luna?" she asked.

"Just darkness."

"Yes, it was darkness. But it was what was in this darkness that..."

She took a deep breath.

"I saw ponies, dead. Unspeakable things had been done to them. Carnage, slaughter. Incredible atrocities."

"Who has done that, sister? Where?"

"I don't know who has done that, but I know where: The town of Hope at Equestria's western border."

"Then we will go there and find the culprit. Have you seen anything that could give us a hint at who it was?"

Celestia though for a second, then she slowly said:

"Yes, I think there was something, but it was just a symbol."

"What kind of symbol?"

"An eight-pointed star."

Antonius took a deep breath, making a disgusted face, and the princesses turned towards him.

"Antonius, do you know that symbol?" Luna asked,
"do you know who is responsible for this?"

Antonius nodded.

"Chaos," he almost spat.

"You mean the Chaos that was responsible for the Horus Heresy? That Chaos?"

"Definitely that. Seems you have become a part of our galaxy. Now, we must ensure that you survive."

Author's Notes:

Caution:
The next chapter will have a heavier emphasis on the tags 'gore' and 'dark'.