"So tell us, my human friend; what dost thou think of Equestria's mettle?"

Princess Luna and I were strolling together through the castle at night. Over the course of days and nights, I had become something of a minor fixture in the castle; neither Princess had been so foolish as to put a potentially valuable-- and dangerous-- strategic utility such as myself far away from themselves. No boast there, just fact: I was, after all, the first example of my entire species to fall into their hooves.Tell me, after first contact, how far away would the President of the USA keep the first alien from outer space from his immediate reach? As such, I was quartered with the royal family itself  (yes, Prince Blueblood is a bit of a ponce. but on the other hand Princess Cadence is quite charming...) and spent much of my time in the Princess' company. It was making me feel rather like an exotic pet, but I managed to cope with it.

My erratic sleep schedule in Earth had come to some utility here in Equestria: it meant that I could freely socialize with both the day and night courts, and their respective Princesses.... while they begged me to regale them with stories of my homeworld or, less subtly, pried for useful tactical information about my people. Some people would think me traitor for willingly giving up my race's "secrets," but I felt no compunction to hold back. These ponies, while not as light and fluffy and harmless as our entertainment would have them, were still innocent souls who at least deserved to know what they were in for, should my inadvertent arrival in their world be a herald of inevitable contact with my race.

That evening Luna was taking her nightly constitutional, strolling through the castle and its grounds, and had asked me to accompany her. I had accepted. We were now walking along the parapets high above the castle grounds, out in the warm night air. The topic had drifted about to this. "Mettle?" I repeated. "I'm not certain how you mean."

The Princess of the Night hesitated. "We shall-- try to speak more clearly, then," she said. "Thou knowest the rumors about thyself that run abroad. Chiefest being that thou art a... forward scout for thy people, sent ahead to assess our strengths and weaknesses..."

"For conquest, yes. I've heard those." From several snotty noblemen... nobleponies? who I assure you were anything but noble. "You know, they're not a very subtle lot, your nobles."

"How so?"

"Well, I can tell they obviously don't believe it. If they did they wouldn't be stage-whispering the accusation to each other within my earshot. I've never been in a royal court in my life before arriving here, and even I'm more subtle than that."

Luna chuckled... a charming sound from someone who spends so much time trying to look and sound so stern. "Be that as it may... "

"Seriously, Highness, I would hardly pick someone like myself-- " I gestured down at myself-- "to be a spy or scout. I have no training, no appropriate skills, I'm in ill shape... as your own doctors can attest..." I frowned unhappily, remembering. I'm no athlete or terrible risk taker, but I've had some misadventures that have left their marks on me. The unicorn's shock at finding burn scars on my heart had been something to see. "I'm still so overweight that I couldn't even run a respectable distance. I'm the least likely secret agent you can imagine."

"One might point out that the best secret agent is the one thou wouldst least suspect," Luna teased. "Twould be a clever double bluff on thy part..."

I snorted. "Too many clever tricks and you eventually outsmart yourself," I said. "Still I won't blame you if your people suspect me. It's simply smart to keep that possibility in mind."

"I do not... truly suspect you," Luna said. "Nevertheless... if thou WERE assaying us for our mettle..."

"Evaluating you for conquest, you mean?" I said.

Luna nodded. "What wouldst thou say of us, and our ability to... hold our own, I believe is the phrase-- against an invader?"

I looked down at my feet and bit my lip. I had been thinking about that and I didn't like the conclusions. "I'd say that you were all but dead meat."

Luna stopped on a dime, head rearing back in surprise. "Thou art quite blunt with us, friend," she said, perturbed.

"It's blunt facts, Princess," I said, shrugging. "I'm no strategist or tactician, but I know enough to know that, in a throw down fight with one of the nations of my world, Equestria would be hosed."

Luna frowned. She bit her lip, obviously holding back a prideful retort--- probably one in Royal Canterlot Voice-- about her people's martial valor. ".... Elaborate," she said. "Please."

I shrugged again. Where to begin? "I've told you about my world's technology," I said. "Because of, well, because of who we are, we have fought a lot of wars. And every bit of our technology has gone into our militaries.   We have planes that fly faster than any pegasus. Armored vehicles that could smash through this palace's walls. Bombs that could level it. Guns that can kill from so far away that you never hear the gunshot before you feel the bullet hit you. Poisons, diseases, gases..." I shook my head. "If they could open a portal here, and decided they wanted to destroy everything, they could simply chuck nukes through the open hole till nothing was left but ash. If they wanted to conquer, even the cheapest third-world pothole could send troops and machines and weapons through that would devastate your kingdom."

Luna looked horrified, but rallied. "But what of magic? What of the dragons, of the ursa minor and major, the---"

I shook my head again. "still no good," I said. "Even if your magic and magical beasts put you on parity with a modern human army, and believe me, I'm sure your magic would give them absolute raving conniption fits..... you're still so tactically backward it wouldn't matter."

"Tactically backward?..."

I paused for a moment, thinking it over. "Let me take it from the top," I said. "Magic gives you an incredible advantage on a modern battlefield-- or it would, except for one thing: range. How far away can the typical unicorn cast a spell? Not much farther than a typical pegasus can launch a spear while in flight, or trigger a lightning bolt or rainstorm. A distance of what, a mile, at most? The average sniper can shoot someone from two. And they have cannon that can fire twenty miles or more, and missiles that can fly a hundred miles or more...."

"I've looked over your history books and looked at your soldiers training. You're still using battlefield tactics that were outdated on Earth in the era of Napoleon. Your long-range communication consists entirely of LETTERS, except for a bare handful delivered by dragon fire. Humans have cell phones that let them talk to people instantly, on the far side of the globe. You have high-flying pegasi for intel. Humans have spy satellites-- tiny artificial moons--- that can photograph entire battlefields, flying drones that can send real time photographs back to base instantaneously, and high flying planes that literally race faster than a bullet and cross entire continents in an hour. An invading human army would conquer half your planet before you or Celestia got the letter notifying you that the invasion had started."

"To top it all off you have one superweapon that I know of. One. And it's composed of six separate parts, each requiring a separate, VERY SPECIAL pony to operate, and that only works when all six components and operators are in close proximity and absolutely everything is working exactly right. And if you managed to fire it off once, you'd never get a chance to use it twice, because the enemy would know exactly how it worked just from watching and would send a single man with a gun to eliminate it entirely from play with one bullet to one pony head."

Luna looked at me in horror. The expression on her face was indescribable; I can only imagine it as the look on the face of an ant who has just been given a full description of a hiker's boot. "what then.... are we to do?" she finally said in a half whisper.  "You counseled us before to meet your people from a position of strength. How are we to do this, if e'en a fraction of what thou hast told us is true?"

I finally had to be honest with myself. "Simple," I said. "Don't. Don't make contact with humanity, if you can at all avoid it. Don't let them come here. Don't let your people go to them. Stay away from us, as long as you possibly can." I turned and started walking again, trying to keep the princess, this poor thousand-year-old child, from seeing the moisture welling in my eyes.

She easily caught up and matched her stride to mine again (curse my fat slug of a body!) For a moment neither of us spoke. "That is not an option," she said. "Thou knowest. Once a thing has been found---"

"-- it is only a matter of time before it is found again," I finished. "Yes, I know. I stumbled into the portal, sooner or later someone else with more ept will stumble on another.  But it's the only thing that comes to mind right now. Delaying the inevitable." I shrugged. "Delay it long enough, maybe by then your world will have advanced enough to stand its ground against the despots and monsters of my world, who knows?"

We resumed a more sedate pace. "Thou art rather hard on thine own species," Luna noted. Not without sympathy.

I didn't disagree. "True enough," I said. "...Early on, I told you of my beliefs..."

Luna nodded and nuzzled at the pendant hanging around my neck. It was a crude bit of metal on a thong: two nails welded together in the shape of a cross--- the one thing I'd had with me, other than the clothes on my back, when I fell through the hole in the air that brought me here. "It hath... familiarities and similarities, here and there... to our own understandings," she noted.

I made an acquiescing noise. Comparative theology was one of the many topics mulled over since my arrival: I'd long ago come to peace with the personal notion that whatever covenant these creatures had with God, it was unique to them and not the same as the one humanity had with Him. " Well, princess, one of the articles of my faith, probably the first,  is that we have to accept the truth about who and what we are," I said. "And  as one of our greatest theologians put it: "We are all fallen creatures, and very hard to live with." All of us, Fallen from grace. Even those who have sought and accepted redemption, Fallen.  Even the very best of us. I know what my people are... what I am. And what harm we can do, even with good intentions, if we are given free rein."

"And I especially know what the worst of us could, and would do, if they were given free rein here."

"So that is thy only advice to us?" Luna said gently. "To delay the inevitable? Sometimes the inevitable comes tomorrow. What then?"

I scowled. "I thought I made it clear already. There IS no solution. If humanity arrived here with villainous intentions, they would hold an insurmountable technological advantage. You're asking me to devise some--- some magical way to... remove... that... advantage...."

I stumbled to a halt. Luna looked back at me in puzzlement; I can only imagine how outlandish my expression was.

"No," I said. "It couldn't possibly be that simple..."