Lock and Key

                                          Two demons stand by at the end of a dark hallway.
    "The deed is done, Leviathan," says the one covered in blood, holding a blade in his hands.
    "Good, that's good..." says the other, fidgeting with his hands behind his back.
    "He's as dead as I'll be if the other Princes ever find out!" The blood-soaked dragon chuckles, tossing an emerald dagger into the air only to catch it a moment later, "Hopefully by then I'll be more powerful than they could ever imagine."
    He is missing both of his antlers and seems to have just come from a fight. Large tears have absolutely ruined the back of the suit jacket hanging loosely from his shoulder.
    "...Yes, yes, no need to worry over that, Legion! No need at all." says the Prince, seeming nervous and rather lacking in confidence compared to the other. "You'll be made Prince soon enough." He seems to find some with that statement, fixing his posture with a small smirk on his face.
    "Now, to seal it," says the Prince, speaking with a tired sigh as he steps back, "Can't have anyone stumbling across the corpse."
    "Indeed." The dragon turns towards the dark and empty corridor from which he had came and holds out the emerald dagger. For someone who had just committed regicide, his weapon looked immaculate. No imperfections or blood, aside from where he gripped the handle tight. His hands were freshly bloodied from the act, after all!
    The walls and floor began to shift, closing together around the blade. As quickly as they had begun to move, the corridor was no more. A recession in the otherwise pointless dead-end was left in it's place. 
    He pulls the dagger from the wall, pleased with his work. 
    "Just as I had intended." He turns to the Prince, holding the blade out. "I trust in you to make sure this shall never be rediscovered, yes? I have given you the lockbox. What you do after this is placed inside is entirely in your hands."
    The Prince takes the dagger, examining it the way only a fool would.
    "Don't do that," the dragon reaches and pulls the Prince's hand away from the blade, "You'll cut yourself. No wonder you needed me to do this for you."
    The Prince, frustrated, looks away with a huff. "Yes, yes, I know."
    The demon's eyes then meet, both staring at each other.
    The Prince speaks first.
    "You can trust me, Legion. It will be placed under lock and key for all of eternity if I so wish. It will be stashed away in my own personal hoard. No one will be able to find it. Not unless I allow them to."
    "Good. I would want it no other way."