ASSASSIN [hyperventilating]:
I can't do this I can't do this I can't do this I can't do this

TRAINER [slapping ASSASSIN upon the head, waking him from a stupor]: 
Get ready, boy. Now's the time. 

[ASSASSIN obeys, quiets down, tries to control his breathing.]

TRAINER:
Hit the target.

[ASSASSIN takes a slow breath in. He breathes out as the trigger is pulled, a beat stagnates the action entirely. . .]
ASSASSIN [frightened]:
Sir?

TRAINER:
Shoot the goddamn gun!

ASSASSIN:
I am, it's not working!
[ASSASSIN demonstrates the failing gun. No bullets fire.]

TRAINER:
Did you forget bullets?

ASSASSIN:
Of COURSE not. . .  
[ASSASSIN violently throws the gun down to the ground as he says "COURSE". It does not hit the ground. It remains suspended in the air. Both men blankly stare at this phenomenon.]

TRAINER:
Get it down, now!
[The gun fires as ASSASSIN reaches for it. It drops into ASSASSIN'S hands upon firing itself. ASSASSIN throws the gun to the ground and there it remains. Neither man picks it up.]

ASSASSIN [fumbling for the walkie-talkie on his belt, speaking into it professionally]:
Target down.

WALKIE TALKIE:
You two come down discreetly and pick up the reward. History will remember you well.