It was a simple task for Zulu, all he had to do was interrogate a young stallion who had infiltrated a gala at Canterlot Castle the previous night. General consensus was that the colt had simply wandered in looking for cider then made a flank of himself on complete accident, though with a recent uptick in changeling attacks the Royal Guard didn't risk taking such an intrusion lightly.
As for the facts, the colt had showed up a few hours into the event through unknown means, gotten severely inebriated at the open bar, somehow he ended up in possession of a priceless artifact, and fled when confronted by security. Fortunately, the colt was drunk or stupid enough to run directly into the chest of Celestia, this knocked him to the floor where he was swiftly apprehended.
Slowly Zulu descended the staircase leading to a dungeon. Still a site on castle grounds the jail was decidedly ornate, far more decorated than deserved considering its occupants. Zulu assumed the numerous portraits of Celestia and marble walls resembling her coat were a sick form of mocking those imprisoned by the monarch, he wouldn't put it past her.
Zulu stomped to the eighth door on the right, playing up his hoof-steps to intimidate the cretins behind bars. Inside a small area separated the entrance of the room from the entrance of the cell. A young unicorn laid motionless upon the cells bed with his face towards the wall, he was obviously past the age of belonging in a schoolhouse but still too young to be called a proper stallion.
"Good morning, Colt." Zulu sternly spoke.
"Keep it down!" The young stallion loudly requested, "My head hurts…"
"First hangover I take it?" Zulu questioned, intentionally raising his voice.
"Yeah…" The colt moaned in pain.
"That's what you get…" Zulu mumbled with a punctuating chuckle, "Sorry to hear that, regardless, I'm going to have to ask you a few questions."
"No," The colt simply replied, "And go to the Moon while you're at it."
"Cut the profanity, prisoner, you could just as easily be in Tartarus!" Zulu snapped, "Now, comply."
"I'm not getting up." The colt protested, "I'll answer questions but I'm not getting up."
"That's fine, I guess," Zulu returned to his relatively calm tone, "Now, state your name."
"Spitfire." The colt mocked.
"Cut the crap!" Zulu sternly requested.
"Fine… Paper Pen, I'm Paper Pen from Manehattan… I might have told a few ponies last night that I was Prince Harlan of Saddle Arabia, I honestly can't remember." The colt complied.
"Right, Paper Pen of Manehattan…" Zulu recorded the answer in a notebook.
Only now had Zulu actually looked at the unicorn. Pen had a shining white coat and dark hair, things that made him look ever so slightly like the late Legacy Heart. This was no surprise, everything reminded him of her nowadays.
"So, why were you at the gala?" Zulu interrogated.
"Free booze?" Pen answered, confused, "I get you lot are poor detectives but that much isn't hard."
"Due to recent events we're operating under the risk you could be a changeling," Zulu explained, "We wouldn't throw a drunk in here."
"Really, you think I'm a changeling?" Pen laughed, finally showing an emotion other than snark. Something about his laugh seemed oddly familiar to Zulu, though too distant a memory to fully remember.
"You snuck into a party and got your hooves on a powerful artifact, as far as Celestia is concerned that's a major breach of security." Zulu explained, "Which leads me to my next question, why were you in possession of royal property?"
"I swear it was just on the floor, I was gonna return it… somepony else probably tried to take it," Pen defended, "But then you jerks called me a thief and ponies got the wrong idea!"
"Likely story, you really expect me to believe that the only pony there without an invite, who was also drunk, and fled from security, isn't so low as to resort to theft?"
"I mean, yeah ?" Pen shrugged, finally rising to look at his interrogator.
Zulu could see Pen's mane now, it was in a state of mess, of course, though in such a state that he highly doubted it had seen many better days. Long streaks of jet black hair hung from the hunched pony's head, covering his face and hiding his gaze.
Eerily enough this reminded Zulu of the time he'd seen the tyrant Chrysalis within her throne room, a long mane of tattered hair like torn fabric covering the creatures face to hide plotting eyes. It was that night he'd lost his left eye, that night he'd sworn to protect his nation from the insectoid menace. He hated how this colt made him feel that way again, he wasn't supposed to know fear anymore.
"Tell me the truth, Pen, if you are honest, we can work out a deal, and even should you be a changeling… I promise you your life, at least." Zulu grimmly commanded.
"I did!" Pen insisted, finally wiping the hair from his face, "I'm not a thief and I'm not a changeling, all I wanted was a couple drinks!"
What Zulu saw on the unicorns face made the warrior guard captain wish he was talking to a changeling, buck, he would have rather the colt was Chrysalis herself dead set on finishing the job she'd started so long ago.
Two gray eyes stared into the one remaining of Zulu's. They had the exact same eyes, a color too rare to be common coincidence.
A long silence passed of Zulu only being able to stare at the colt in absolute shock. It had been so many years since he'd abandoned his own foal, so many years of regret, all of it only for this to be the first time he'd spoken to his own son. Zulu had dreamed of this moment, fantasized that one day he'd reach out and find the colt, that one day he'd finally be able to properly apologize and make up for the terrible thing that he had done, that he'd be able to be a better father than his own.
"Hey, dude, you good?" Pen asked with concern towards the paralysed guard captain.
"You… I'm…" Zulu struggled to find words to say, words were never his strong suit. Maybe if they were, he thought, he could have convinced the Princess to let Pen stay with him, maybe he could have convinced his Love to never go on such a dangerous mission. "You…"
"I'm what?" Pen inquired, rolling his eyes, "A changeling?"
"Released." Zulu sighed, giving up, "I have all the information I need, you're no longer under suspicion."
Silently, Zulu moved to release the colt. Each step he took towards his son hurt more than any stab wound he'd ever experienced, he'd never even met an arrow or bolt so vile.
Even worse was the sensation of Pen trotting past him. He wanted so badly to say something, anything to properly talk to his own and only son but he just… couldn't, every word froze, died, and decayed to bone before leaving his throat. Zulu attempted desperately not to cry as the rooms door shut, Pen was out of his reach and he had no idea when, if ever, he'd see his son again.
"I- I'm sorry…" Zulu struggled to force his words to even the empty room, "I'm so sorry…"