Sometimes Flash really hated being a Guard. Every time he put on the armor, and sometimes after he took it off, he found it impossible to just relax. Everywhere he went, he was constantly looking around, noticing entrances and exits, lines of fires, potential hazards...taking a mental catalog of everything he saw, heard, smelled, tasted and felt. Sometimes, he could only see other ponies as either "threat" or "non threat," as if the armor included some sort of glasses that filtered his vision.

Like here, standing in the lounge of the Ponyville Cancer Research and Treatment Center, examining everything and everypony who had gathered here for Twilight's opening speech. The doctor standing on the other side of Twilight at the podium: earth pony, male, middle aged. Relaxed posture, no sign of nervousness or concealed weapon. Non threat. The assistant doctor next to him. Pegasus, male, early thirties. Slightly tense body posture, looking away. Adjusting the sleeve of his white coat to cover a strangely familiar faded tattoo on his foreleg. Possible threat. The janitor on the other side of the room, wheeling up to a desk and bending over a clipboard, signing on with his left hoof. Unicorn, uninterested, bored expression. Non threat. The little foals and fillies that stood before Twilight, gazing up at her in awe and delight, hanging onto her every praising word. Non threats. That's all he saw them as.

Twilight was just finishing up her speech opening the new children's wing and declaring her hope that the research that would take place within would one day unlock a cure for cancer. The entire audience burst into applause, stamping their hooves against the tiled floor in delight. Everypony except him, standing stern sentinel next to the Princess. This was a happy occasion, darn it all: why couldn't he be happy and enjoy time with his marefriend?

"Thank you for your kind words, Princess Twilight," Doctor Caduceus said. An earth pony with a blue mane, graying at the temples, and kindly blue eyes, his cutie mark was a golden caduceus that stood out against his brown coat. He took Twilight's place at the podium, looking out into the crowd of patients and fellow doctors. "We should all be very thankful for Princess Twilight's continued support, for without her, none of this would be possible. So let's have another round of applause for her, and for everypony who continues to aid us in our battle against cancer!"

There was another round of applause. Flushed with embarrassment at the praise, Twilight shifted slightly, her wings fluttering against her sides. Flash had to force back a smile at the cuteness. He couldn't afford to break character, not in public.

"Excuse me," a voice said from behind him. Turning, Flash saw a messenger pony holding a telegram in his mouth. "Message for Corporal Sentry."

"Can it wait?" Flash asked. His question, however, was quickly answered by the bright red "URGENT" stamped on the envelope. Flash took the telegram, opened it up and read the brief message inside.

"Somepony at PCRTC works for Z. Threatens patients, blackmailed bank manager and jail warden. You need to find him. Phil."

Slowly, internalizing his racing thoughts and chilling emotions to avoid giving anything away, Flash looked up and scanned the room. Doctor Cadaceus was still speaking to Princess Twilight. His assistant doctor was standing next to him moodily, seemingly unable to meet Princess Twilight's gaze. A group of doctors and nurses, clad in white coats, was now shepherding the children into the new wing, taking them to their new beds or off to a treatment room. Support staff, clerks, secretaries and janitors mingled in the crowd. In Flash's vision, every single one of them had suddenly become "possible threat."

Forcing himself to move calmly, he walked to Twilight's side, gently pulling her aside. "Flash!" Twilight protested. "I'm in the middle of—"

"I need to get you out of here," Flash whispered into her ear, showing her the telegram. Her lavender eyes widened in surprise as she scanned the message within, then panned over the foals and fillies.

"We need to find him," she whispered back.

"I need to find him. You need to get out of here," Flash hissed back, taking her hoof to guide her from the room.

"No!" Twilight replied sharply, pulling her hoof from his grasp. "I'm not just some helpless damsel! These ponies are under my protection, too!"

Flash hesitated. Twilight Sparkle was certainly no helpless damsel. She was the mare he loved with his whole heart, the light of his life. And she was currently willingly putting herself in the same building as a possible killer, because the ponies here were hers, under her protection as well as his.

"Your Highness, is there a problem?" Doctor Caduceus asked, walking forward with the moody doctor at his side. Flash finally recognized his companion: Doctor Winged Cure, a white, green eyed and blonde maned pegasus with a cutie mark of a winged cross, the assistant head doctor of the research center.

Twilight and Flash looked at one another for a moment, then Flash sighed through his nostrils and nodded subtly. "We need to speak to your staff members," Flash said. "We have reason to suspect that one of them might be involved in...er...criminal activity."

"What?" Doctor Caduceus asked, his wrinkled eyes widening in horror. "How could you think that? Everypony here is dedicated to the health of these patients; they couldn't possibly—!"

"Doctor, I'm sorry," Twilight said, stepping between the stallions. "This is just a suspicion. We'll just talk briefly to your staff members, just to check and make sure that everything's all right."

Caduceus frowned, chewing on his lower lip. Winged Cure was shifting nervously, looking at everything and anything except Flash and Twilight.

"Well, all right," Doctor Caduceus replied. "But I'm certain that nopony on this staff is a criminal."

A muscle twitched in Flash's jaw and he glared at Winged Cure, who swallowed nervously, sensing his gaze. He had just remembered what that faded tattoo on his foreleg was, and what it meant.

"And I believe you," Twilight said reassuringly. "But we do have to make sure."

"What do you want to know?" Winged Cure muttered at Flash's knees.

"Does the name Zugzwang mean anything to you?"

"No. Should it?" Winged Cure replied, making eye contact for the first time, revealing a carefully constructed cool expression. Yet he could not control the nervous twitch of his tail, nor the way his knees were pointed towards the double doors leading into the children's wing, indicating a desire to leave as soon as possible.

Flash maintained eye contact for a moment more, then stepped aside. "That'll do for now." The doctors left quickly, disappearing into the new wing. The double doors swung shut behind them.

Behind the doors, the killer shifted uneasily. If the Guard was asking questions, that meant that they were onto them. It would only be a matter of time before they found him, and sent him away to prison.

No! No, he wouldn't go back to prison, wouldn't go back to the stone and iron hell!

Forget what Zugzwang told him. He needed to get those two out of the hospital now.

"What was that look about?" Twilight asked Flash back in the lounge, giving him a scathing look.

"You didn't see that old tattoo on Winged Cure's leg?" Flash asked. "I did. A skull with a snake coming out of the mouth. That's a Sinalope cartel tattoo."

Twilight's eyes widened in horror. "No. He's not like that. I know him; he's kind, he's helpful, he truly cares about the patients—"

"He was part of a gang that smuggles drugs and executes whole families," Flash said coldly. "I grew up with ponies like him in my neighborhood in Philly. Ponies like that don't change. Ever."

"Ponies do change, Flash!" Twilight shouted back. "Winged Cure can't be Zugzwang's accomplice, he just can't!"

Flash was just about to point out that at this point, he had to consider all the staff members a suspect, when a piercing scream rang through the hallways of the hospital. The two ran into the children's wing, passing crowds of frozen doctors and patients as they followed the echoes of the scream into a patient's room. A nurse was staring at a patient's bed, her hooves up to her mouth in horror.

The small filly lying in the bed was dead, her blue eyes staring at the ceiling and her mouth hanging open in shock. A crimson bloodstain spread across her light blue shirt, upon which a note was lying.

"BACK OFF OR MORE OF THEM DIE."

"Why don't we just shoot him?

"You know what the boss is like. Him and his games..."

The voices sounded like they were coming from the bottom of a deep well, but they roused Phillip from his unconsciousness. Opening his eyes, he saw that he was lying in a small, dark room, a dying glimmer of light from the closing door penetrating the room. In his few moments of visibility, he saw that the room's only contents were a table with two candles, an envelope and a red button. Then the metal door slammed shut with a crash.

Shaking off the dizziness, Phillip got to his hooves and stumbled through the darkness to the door. Just to satisfy himself, he seized the handle and turned it, only to receive an electric shock that forced him back with a cry of pain. Rubbing life back into his foreleg, he turned then to the table. Taking his flashlight from his vest, he turned it on, illuminating the table and its strange contents. Taking the envelope, Phillip tore it open and examined the message within.

Dear Phillip,

I suppose you're wondering why you're still alive. Believe me, I was very tempted to just kill you while you were asleep. It would have saved us both a lot of trouble: we both know one of us is going to kill the other one day.

But such a death was unworthy of both of us, Phillip. And besides, you're right: I really can't resist being clever. It is a weakness with me, but to be fair to myself, it is my only weakness.

That's why I'm so glad you came to my little party. It feels wonderful to have somepony who's both able and willing to play with me, and I don't want to lose that just yet.

I can't let you leave and warn your friends just yet—you still have a lesson to learn, after all, about the necessity of sacrifice—but I will give you this chance to free yourself early.

The two candles both burn out in an hour, but at uneven rates. When you push the red button, the door will unlock in 45 minutes for one minute before locking itself again. You'll notice that I have taken your watch. If you can figure out how to use these materials to get out, you'll be home free. If not, I'll let you out when I come to tell you that your friends are dead.

Viel Glück, liebling!

—Zugzwang

Looking down at the two candles and the red button on the table, Phillip felt his pulse accelerate, both in anger and in fear. To Zugzwang, the lives of his friends and of his own were nothing more than a game; they were, to him, no more than chess pieces, to be manipulated as he saw fit and sacrificed whenever it suited him. And now Twilight and Flash could be sacrificed, just to prove a point. Why, why had he have to get involved? Why did he have to allow himself to be pulled into this sick, twisted game?

No. Calm down. He had to focus. Solve the puzzle, get out of the room. Closing his eyes, Phillip exhaled a long, slow breath out of his nostrils, dispelling his storm of emotions and allowing his rational mind to take over. Staring down at the two candles, he began to imagine solutions.

The game was far from over.

Author's Notes:

This is not good.

(No, really, it's not good. I'm just struggling on at this point.)