The warehouse was empty, except for the two solitary figures standing at its center. The TimeLords stared at each other intensely, neither moving an inch, almost daring the other to do something.
"What are you planning?" the Doctor enquired.
The Master smirked. "What makes you suspect I'm up to something?"
"You're always up to something."
"Well, I'm not. I was simply looking for this." The eccentric Gallifreyan held up a small metal device, similar to a revolver. "And for once, Doctor, you're not going to stop me." He aimed the device at his arch-enemy, then smirked and pulled the trigger.
A bullet whizzed past the Doctor's face, crashing into the shelves of stored weaponry.
"You missed," the Doctor commented.
"Did I?"
He turned toward the shelves; the bullet had ricocheted off of a metal shelf, shot towards the ceiling, spun momentarily in the large fan, fell back to the ground, slid across a conveniently placed ramp, and finally came to rest in the Doctor's left arm.
The TimeLord recoiled in pain, grabbing his wounded arm. The Master smirked devilishly, pocketing the weapon.
"As you can see," the evil renegade explained, "the bullet is coated in microscopic nanobots, which are already invading your bloodstream and headed for your heart. These bots allow the bullet to bounce off any object, excluding its preprogrammed target." He turned to leave, and added with a maniacal laugh, "Enjoy your Regeneration, Doctor."
