This 'reference guide' was an utter disappointment for Antonius. The only definitive information it held was that there were six Elements of Harmony, one of them was unknown, and their last known location was a castle located in the forest he had appeared in.

According to the information he got from Twilight on their way to Ponyville, they knew much more about those Elements now and this book was outdated.
Great.

Well, he could still asked them about the Elements. Great idea:

"Hello, I'm this strange warrior from the Imperium and I would like to know EVERYTHING about your anti-Chaos-super-weapon.
No, I won't try to acquire it, it's just curiosity."

Really a great idea. The ponies were naive, but they were definitely not dumb.

Perhaps he could inconspicuously direct a conversation towards that topic?
He would find a way. In the meantime, he would be patient.

Antonius put the book back into its place, then he took a look around. The sun had not yet risen, but it could not take long anymore until it did.

Just as he wanted to look for a new book, he heard a door upstairs.
A few seconds later, Twilight came down into the library, followed by Spike.

"Good morning, Mr. Varus. How's the night been?" she greeted.

"Informative."

"Err... good. I should probably tell you that I told the princesses of your arrival. I hope you don't mind that.
They'll be coming this afternoon to meet you. I'm sure you will like them, they are very nice ponies."

"I don't mind that. In fact, I know they will be coming."

Twilight looked confused now.

"Huh? How do you know?"

"I met Princess Luna a couple of hours ago. She invited me to join her patrol of the forest."

Twilight's eyes grew bigger.

"You already met her? Did you join her? Did everything go fine?"

"Yes, yes and yes; just a pack of Timberwolves. No problem."

"Sounds like an eventful night.
What about the maps and the book? Have you learned what you wanted to know?"

"I have, Twilight. Tell me, do you always get up before dawn?"

"No, but I have to prepare breakfast for six ponies, a dragon and you. We must start our excursion as soon as possible."

Having said that, she and Spike vanished through a door into another room.
Antonius was alone again, but not for long. Soon, he heard a knock on the front door. As he was the only one available, he opened the door and was greeted by Applejack:

"Good morning, Mr. Varus! I thought I come a little earlier and bring some food, just in case."

'Some food' was a nice expression for the cart she was trailing behind.

"Could you tell me where Twilight is? Still sleeping?"

"No, she has gone through that door over there, Spike in tow."

"Ah, the kitchen. Thank you."

Applejack parked the cart outside the library and carried its contents to the central table, then she followed Twilight.
That was the moment someone else knocked at the door.

"Yesterday evening a ladder-replacement, this morning some kind of porter... I wonder what I will be at noon..." mumbled Antonius as he went to open the door again.

This time, it was Pinkie Pie - also with food.

Within the next few minutes, all of Twilight's friends arrived at the library, each of them bringing something to eat, even if it was just Rainbow Dash's potato chips. Rarity was the last of them, with a picnic basket.

All told, they probably had enough food now to feed half of the town. Most of it was some kind of sweet, and no meat was to be found anywhere. The ponies on this planet were no true herbivores, but they definitely were vegetarians.

The group gathered around the central table and started eating. While the ponies talked a lot during the meal, Antonius was mainly busy filling his stomach with a lot of food. The mares noticed that fact soon, and Twilight asked him:

"Sorry, Mr. Varus, but, how many stomachs do you have?"

"I bet it's eight!" interrupted Pinkie Pie with a smile,
"That would be fitting for an alien life form!"

Being called an alien again was more than annoying, even though it was not exactly wrong, so Antonius said:

"Stop calling me alien. Use my name instead, Ms. Pie."

"OK, if you call me Pinkie!"

"Accepted."

"Oh, and I think you don't need to call anypony of us here 'Ms.'. The Names are enough."

"As you wish."

"May we call you 'Antonius'?"

"If you insist..."

"Now, Antonius, do you have eight stomachs?"

The Space Marine sighed.

"No, it's actually just one, plus the pre-stomach mentioned yesterday that does no actual digestion. Why do you ask?"

Twilight took over the conversation again:

"Well, Antonius, you seem to be very hungry."

"The nutrition value of normal food is quite low for a Space Marine, I have to compensate for that by eating a larger quantity."

"That's no problem," Applejack interposed,
"I'm sure my family can grow more apples than you can eat."

"That's good to know," said Antonius,
"but that won't be sufficient in the long term.
Humans are omnivores, I will sooner or later need some meat, or at least some sort of nutritional supplement."

"No trouble at all," Twilight told him,
"we also know meat-based food because of foreign guests who visit Equestria. We will find something, just tell us when you need it."

This was the moment Spike made a strange noise, like he was going to throw up every second.
Was the idea of meat that disgusting to him?
He burped fire and out of the flames a scroll materialized.
WHAT? What the hell did he eat?

The ponies were not the least bit alarmed and Twilight grabbed the scroll with her magic.

"Oh, another letter from the Princess," she said as she unrolled it.

Her eyes grew bigger.

"They want to solve the mystery of the 'Southern Star' with Antonius' help!
That means they will stay for longer! We have to prepare the telescope and get some more food! And I almost forgot cleaning the library!
But we wanted to have a look at that clearing today! We can't do all of that!"

"Easy, sugarcube," Applejack reassured her,
"I'm going to take care of the food."

"Oh, I'll help you!" Pinkie offered,
"Cakes from the Cakes for the princesses!"

"I will tidy up the library," Rarity offered.

"Umm, I will also stay here and help Rarity. I think it's much better than going into the creepy forest," said Fluttershy.

Creepy? It was just a forest with equally strange and pathetic animals.
Perhaps Antonius could show some 'good will' if he tried to cheer her up, so he told her:

"You do not need to worry about the creatures that live in there. I am positive I can protect you from them."

"Umm... Well, I'm sorry, but... I'm afraid of you, too."

Hmm? Usually, he would have taken that as a compliment, in his current situation, though, it was rather unfavorable.
He should do something about it.

"You do not need to be afraid of me," he told her.

"Umm... Okay?"

That did not sound very convinced. Perhaps a little explanation would help?

"You do not intend to kill me, do you?" he asked.

The ponies and Spike looked confused and Fluttershy paled.

"N-no."

"Do you want to wipe out, oppress or otherwise harm mankind?"

Fluttershy started shrinking visibly.

"N-No."

"Then, as long as you respect me, you have no reason to fear me."

"Okay."

That sounded even less convinced than before. His attempt had backfired. Thoroughly.

Rainbow laughed:

"You really have strange methods of cheering ponies up!"

Well, they had obviously at least understood his intention.

"Okay, back to business," Twilight said,
"we still have to deal with the telescope. It must be thoroughly cleaned for this once-in-a-lifetime opportunity."

"I'll do that!" Spike shouted.

"Okay, girls - and boys - it looks like Antoinus, Rainbow and myself will go into the Everfree, then.
We should start as soon as possible and head to Zecora."

Twilight packed a few things into her saddlebags and the small group left the library and Ponyville.

The ponies were surprisingly fast when traveling, so it did not take them long to arrive at the hut, or hollowed out tree, that was Zecora's home.

They came just in time to see a explosion shoot out of the hut's windows. Apparently, her Everfree-guide had just been terminated. Antonius had his hand on his bolter as they started running towards the door and Twilight shouted:

"Zecora, are you all right?"

To Antonius' surprise, the door opened, and a small zebra with a Mohawk-style mane came out of the hut, coughing, accompanied by vast amounts of smoke.

"Zecora, what happened?" asked Twilight worriedly.

Zecora coughed again and said:

"I tried a new potion for nightmare night,
to give the fillies an enjoyable fright.
However, I won't be using this,
as it does not bring the desired bliss."

A rhyming zebra who almost blew up herself? And she should be their guide through the forest?
What the hell?

Zecora continued:

"Oh, Twilight, it's nice to see you here so soon,
you rarely come here before noon.
And with a new friend of yours,
one who does not walk on all fours!
Hello, stranger, my name is Zecora,
I know in the Everfree fauna and flora!"

Oh great, he just got 'friended' again. He decided not to correct the issue and introduced himself:

"Greetings, Zecora, I am Brother Antonius Varus, Ultramarines 2nd company, Imperium of Mankind."

"Antonius is from another planet and arrived yesterday. He was teleported to a clearing in the forest and now, we want to have a look at that place. Would you please join and guide us?" Twilight asked.

"Twilight, it will be a pleasure to me,
that the place of his arrival we may see!"

She turned to the Space Marine:

"Antonius, you are a warrior, am I right?
In the Everfree, you must be prepared for a fight.
I guess, you know to the clearing the way,
I will be on my guard that nopony goes astray!"

"Accepted. Our first waypoint is a pond I discovered not far away."

Zecora fetched her saddlebags and the group started walking. Antonius took the lead, Zecora, Twilight and Rainbow followed.
There was no path now and the ponies were slowed down quite a bit.

While on their way, Antonius could hear Twilight ask Zecora:

"Zecora, you seem to take it very easy that Antonius is an alien warrior."

"Warriors are not new to my kin,
being ready for battle to us is no sin.
As for the alien, I will just judge his actions,
not his origin or belonging to factions."

Hmm. If she had any idea what was going on in the galaxy, she would judge creatures by the faction they belonged to, but her strange attitude worked in his favor, at least for now.

It took them a while to reach the pond. Once there, Antonius told the ponies:

"I used this pond to clean my armor before I made first contact. Is anyone familiar with it?"

"I can tell you, I know this pond,
of swimming in it I am quite fond!" Zecora told him.

So he had cleaned his armor in Zecora's pool. Whatever.

They went on and made their way deeper into the forest. There were lots of animals and birds, but they did not encounter any creature that had the ability to pose a threat to them. The sun had crossed its zenith when they finally arrived at the clearing.

Twilight had never been that far into the Everfree before. She wondered how Antonius had been able to memorize the way to this clearing; there was no path, and one tree looked like the next one.

"Are you sure this is the right clearing?" she asked him.

"It is."

Twilight opened her saddlebags and took out parchment and a pencil.
She just wanted to cast the first examination-spell, when she heard a crunching noise behind her. She quickly turned around and saw -
Rainbow Dash, eating potato chips.

"What? I haven't had anything since breakfast!" Rainbow said.

Twilight groaned.

"Okay, let's eats something, so that I can examine this clearing without interruptions."

After a quick snack, Twilight lit her horn and analyzed the place, taking notes all the while.

Zecora also had a look at the surroundings, and she seemed a little nervous as she said:

"I have a bad feeling about this,
I think here is a danger that we miss!"

Twilight, being wrapped up in her examination of the clearing, did not pay any attention to her, or to anyone else.
She had discovered a residue of strange magic. It was an unknown kind of magic; not as pleasant and controllable as the one she used, even stranger than the chaos-magic she had felt when she had encountered Discord. It was just a faint trace, but she could nevertheless feel that is was feral, savage and very powerful.
What in Equestria could leave such magic?

She walked around the clearing. This magic residue was strongest in the center and faded towards the rims of it.

She was near the edge when she heard a furious roar. Her head shot up, and she saw a manticore, maw wide opened, jumping at her.
Her heart almost stopped. Everything seemed to happen in slow motion. She saw her death coming towards her, fangs dripping with saliva.
No time to cast a spell.
No time to escape.
She would die here as a lunch for a manticore.
The only thing she could do now was scream.

Suddenly, the air was ripped apart by an enormous thunder that drowned out the animals roar and her scream.
Twilight could see something like a beam of fire shooting past her head and towards the maticore. It hit the creature's head which...
exploded.
Skull fragments, chunks of brain matter and blood darted in every direction.
A torrent of blood hit Twilight directly in the face and she had to close her eyes and turn her head away. She tasted blood, and she knew it was not hers. She immediately spat it out and wiped over her face. The, she turned back to her attacker to see what had happened.

It was a carnage. The manticore's head was gone and ridiculous amounts of blood were flowing out of its bare throat. The whole area was covered with splashes and shreds that a few seconds earlier composed the creature's head.
That, together with the taste of blood that was still in Twilights mouth was too much for her. She threw up.

Damned, this creature had been a sneaky bastard. Despite its size, Antonius had not heard any noises that revealed its presence as it crept up on Twilight. He had to be more alert.
The creature was also pretty fast when it finally attacked, but nowhere near fast enough to outperform the reflexes of an Astartes.

When the creature's roaring head appeared out of a bush, time slowed down for Antonius.
His targeting system immediately recognized the threat and outlined the beast.
His subconsciousness calculated the deflection - which was almost zero at this distance and angle - and he reflexively aligned his bolter.
He pulled the trigger.
The well-known sound of exploding propellant hit his ears and the bolt left the weapon's muzzle.
Once outside, it ignited its own rocket propellant and shot towards its target.
It passed Twilight and continued its way to the creature's head.
The skull was no barrier for the bolt's diamantine tip and it pierced into the brain.
Then, it detonated, obliterating the creature's head from the inside.
Twilight was hit by some of the creature's blood, but she did not suffer any injury.

There was really nothing better than a bolt round to get rid of your enemies.

Twilight spat out, quickly cleaned her face and looked at the creature, then she threw up.

Yes, the ponies really were sensitive creatures.

Rainbow Dash and Zecora had needed a second to realize what had happened.
Now, they raced to Twilight's side and Rainbow shouted:

"Twilight! Twilight, are you all right?"

Twilight just sat there and looked straight forward.
Antonius also started walking in her direction.

"Twilight, are you okay?" asked Rainbow.

Still no reaction from Twilight.

"Twilight is having a shock, I fear,
she saw her own end come too near!" opined Zecora.

Antonius was at their side now.

"Just a second," he said.

Then, he took off his helmet and crouched down. He carefully turned Twilight head a bit so that he could look her in the eyes.

"Twilight? Twilight..."

Her head moved a bit.

"Huh?"

"Are you all right?"

"The manticore almost killed me."

"'Almost' is the most important part here. You're still alive and fine, aren't you?"

"You killed the manticore..."

Antonius smiled:

"That's the reason for the 'almost'."

"You saved my life."

"Anytime."

All of a sudden, Twilight flung her front legs around Antonius' neck, hugged him and pressed her cheek against his.

"Thank you," she said.

The Space Marine was confused. How should he react to this kind of gratitude?
Occasionally, imperial citizens or members of the Imperial Guard had bowed before him to thank him, but he had never been hugged before.
To make things worse, Rainbow joined the hug.

"Thank you for saving Twilight," she said.

"That really was a noble deed,
helping Twilight in her time of need," Zecora added and joined the hug, too.

Worst of all was something else, however:
He was hugged by xenos, so he should be disgusted.
However, he was not. Not at all. Flabbergasted, yes. A bit uncomfortable, too. But not disgusted.
His humanity obviously made itself felt again.

At least he had gotten an answer to his question what he would be at noon:
A saver of life - and a teddy bear.

"Anytime," was the only thing he could say.

The group hug lasted a quite a few seconds, then the ponies let go of him again.

"I've stained all of you," Twilight said as she looked around, obviously still shocked and confused by the manticore's attack and subsequent demise. She was right, however: the ponies had blood on their fur, Antonius on his armor and cheek.

"Sorry," she continued.

She definitely needed time to regain her composure. A little distraction could probably help, so Antonius asked her:

"No problem, but have you found out anything about the clearing?"

Twilight tilted her head a bit, then she twitched and said:

"Oh, oh yes!"

Now, she told in detail everything she had come to know here. When she had finished, she was back to her usual self.

"Does that mean we are done here?" Rainbow asked.

"Yes, we are," Twilight answered,
"We can go home now. Hmm... I totally lost track of time, does anypony know what time it is?"

"Not really."

"According to the shadows cast by the trees, the sun has already crossed its zenith," Antonius told her.

"Do you mean it's afternoon already?" Twilight asked.

"I think so."

"Oh no, I really lost track of time!
The princesses will come to Ponyville in a few hours! We won't be back until then, let alone be able to make some more preparations!
Unless... we can speed up our journey!"

Twilight's horn started to glow and an aura of the same color appeared around her and each of her companions.

"What the..."

was everything Antonius was able to say before he and the ponies vanished into thin air.