The night lay still. Nothing made a sound. Even the wind was silent. Ponyville lay in a tranquil slumber, the Castle of Friendship lifeless and still. Then…

Hoofsteps. Light hoofsteps broke the silence

Seven cloaked ponies approached the castle doors. Opening it silently, they entered. Passing the Map without a second glance, the seven ponies did not even speak to each other. But one's voice spoke, even if he was the only one to hear it.

Gallant Heart scowled. He knew what he had decided to do, and he was ready.

"This will change Equestria for the better." he told himself quietly. "It has to."

"Quiet!" Prince Blueblood whispered reproachfully. The moonlight gleamed off their orichalum daggers as they walked through the hallways, past a statue. The statue equine in shape, around Celestia's size. It bore a great shield and a large sword. It was clad in plate-mail armor unlike anything seem in Equestria, and its head was that of a pony, only obscured by a helmet. It stood dead and silent as the ponies passed it. Gallant Heart glanced at it before quickly rushing forward. Then, the statue's eyes glowed a brilliant blue as the stone turned into the remains of a ghostly warrior. The statue moved and stepped down from its podium. It slowly drew its blade from its scabbard and lowered its head. Changing into a blue ethereal frost lined with crystals, the mist followed the cloaked ponies stealthily until they reached their destination.

The bedroom of Twilight Sparkle, sleeping peacefully within. The ponies opened the door and walked in, their daggers poised to kill. Gallant Heart stepped forward, and raised his dagger above her heart. Then, the mist formed behind him, and as he turned to the sound of crackling frost, the warrior appeared, its sword held vertically with its shield in a similar position. It took a step towards Gallant, who was frozen in fear and shock.

"Begone, foul trespassers. BEGONE!" the warrior spoke before grabbing Gallant and throwing him through the wall of the bedroom with colossal crash and shattering the wall of crystal. Twilight's eyes opened in a flash, along with Spike's. Before they could scream, Twilight ducked downwards to avoid an assassin, who was being swung like a lariat by the warrior. The warrior then slammed the killer into the floor. The assassins lunged as one at the warrior, their daggers poised to kill. But the warrior scoffed and thrust his arms outward, and they were thrown backward by a pulse of magic. Blueblood tried to scamper away, but the warrior grabbed him by the cloak and grasped his throat, beginning to strangle him. As Blueblood began to suffocate and gag, the warrior growled and threw him to the floor with enough force to crack the crystalline floor. Then, he noticed Gallant Heart trying to limp away weakly. The warrior said nothing as he stomped on his back left leg, crushing the bone to powder. Then, as Gallant screamed in pain, the warrior began to throw punch after punch into the assassin's face, breaking the pony's nose. Then, Twilight screamed again, and the warrior ceased his blows, leaving Gallant Heart in a blood pulp. The warrior walked towards Twilight, who was charging her magic to fend him off. Then…

He brushed a stray hair out of her eyes.

Twilight stood in shock as the warrior then kneeled to her.

"You are safe." the warrior said, almost with an air of relief. "I am relieved. Shall I resume my vigil, Element of Magic?"

"Yes...I mean no..I mean, what's going on here?" Twilight said, stammering. The warrior rose and took off his helmet, revealing the head of a pony, with pale lilac eyes and a dark blue coat. His mane was a deep black.

"I am the Sentinel of Harmony." the warrior said. "It has been my duty to protect this castle and the tree of harmony. I have stood this vigil for one thousand years."

"What?" Twilight said, shocked.

"Allow me to start from the beginning." the warrior said. "I have no name or memories. Only a purpose in this life. For when I was alive, I was chosen by the Tree of Harmony to protect it from those who would abuse its power. For a thousand years I stood my vigil, until I was sealed in the Lockbox till when I was needed again. Upon the defeat of the demon Tirek, I was released into the world of the living. My previous purpose fulfilled, I was given a new vigil. Protect the Castle and its Element of Magic from those who sought to do the element harm. Until this night, I have had no need to reveal myself to you and to your companion, thus you had no knowledge of my existence. When the trespassers attempted to assault you upon these grounds, my vigil was disturbed. To those who disturb the vigil of the Sentinel, they are promised and given due punishment."

"You...protected me from them?" Twilight said. "Why?"

The Sentinel picked up one of the Orichalum daggers, and handed it to her. Twilight gasped at the sight of the only metal fatal to Alicorns. She turned it over in her hooves, her face livid in shock.

"They were attempting to slay you while you rested." the Sentinel said. "My vigil forced me to intervene to protect you from any harm."

Twilight sighed and placed the dagger in her nightstand drawer.

"Thank you, Sentinel." she said with a sigh of relief. "Spike?"

"Yeah? Is it safe out there?" came Spike's voice from under the bed.

"It's safe. It was just the Castle's Sentinel protecting me." Twilight said, pulling him out. Twilight told Spike who the Sentinel was, and he sighed in relief.

"I guess I should thank you too." he said.

"It is most welcome." the Sentinel said. " It would be wise to alert the Princesses of Sun and Moon of this. I shall patrol and make sure there are no more hidden threats."

"Thank you." Twilight said. Scribbling a letter of distress to Celestia, and after enclosing the orichalum dagger, Spike sent it with a breath of fire. Not one second later, a reply came.

I'm coming, Twilight. Stay in your room until I arrive.

Twilight rushed out of bed, and helped by Spike, tied up the assassins. After locking the daggers in the kitchen, they brought them to the main hall and lined them up. At that moment, two platoons of Solar Guards rushed in, followed by Celestia, who immediately embraced Twilight with a hug of deep relief.

"Sweep the castle!" Celestia cried.

"That is not necessary, Princess of the Sun."

The Guards turned to see the Sentinel walk forward

"There are no hidden threats in this castle. Have the guards set up a perimeter around this castle. I can account for my actions tonight." Sentinel said.

"Celestia, he's telling the truth." Twilight said, upon seeing Celestia's expression of doubt. "He saved my life and Spike's from those assassins. I promise you, he is no threat."

Celestia sighed and did as the Sentinel recommended. As the Guards hauled the killers outside, Celestia sat down at the table, along with Twilight and Spike.

"You going to sit down?" Spike asked Sentinel, seeing he was still standing.

"Only when I am asked to by the Element of Magic will I rest." he replied.

"You can rest now, Sentinel." Twilight said. The Sentinel bowed and sat down.

"Twilight, what happened here?" Celestia asked. Twilight told her of the attempted assassination, and how the Sentinel easily dispatched them. At the end, Celestia sighed.

"Sentinel, I thank you most greatly."

"Most welcome." Sentinel replied.

"Sentinel…" Celestia said. "Why? All of them are critically wounded, with one on the verge of death! Why did you assault them so...brutally?"

"My vigil demands any who disturb my watch must be dealt harshest punishment up to the verge of death." Sentinel said. "It is my duty, and my burden."

Celestia sighed and set down her teacup.

"Sentinel...your actions were heroic. You saved my student from death. My only concern is that we will not be able to see how far this...web of treason goes." she said.

"As a web catches a fly…" the Sentinel said. "So shall we catch those who have planned and committed this treachery."

"Indeed." Celestia said. "Sentinel, can you watch over my student until her safety is guaranteed?"

"It is never a matter of "can", Princess of the Sun." Sentinel said. "It is a matter of "will." And I will protect her."

Twilight sighed and smiled.

"Thank you, Sentinel."

"Princess!" A guard poked his head in. "One of them is awake!"

"Bring him in." Celestia said. An assassin was dragged in and forced to his knees. Celestia stood before him, unbridled fury in her eyes.

"Why?" she asked simply.

"Because it needed to happen." the assassin replied. "Her schemes and "reforms" threatened Equestria. We simply could not let that happen. We were doing it for Equestria's sake."

"You did it for your own sake!" Celestia roared.

"What we attempted tonight would've led Equestria to GLORY!" he spat, struggling to free himself. Sentinel drew his sword and advanced on him. This sight froze the assassin with fear.

"Sentinel, stop!" Twilight yelled. The Sentinel nodded, stepped back, and sheathed his sword. The assassin was dragged out, and Celestia sighed.

"Guards, gather the Elements and bring them here. We're heading to Canterlot as soon as possible. Sentinel, you're coming as well." Celestia said.

"As you wish." Sentinel replied.