Rook
OK, there are definitely hostiles about -- I've been attacked once already. I'm not taking chances on them getting in the first swing.
Rook will fire at the exposed head (assuming that's what it is).
Rook rolls 1d20+8, getting [18,8] = (26) To Hit
Rook rolls 1d6+2, getting [2,2] = (4) Damage
Rook rolls 1d100, getting [97] = (97) Miss Chance
OOC:
I rolled a miss chance in case you were counting the target as concealed rather than under cover. I'm assuming that since there's a 20% miss chance and I rolled well over that I hit him -- if my To Hit roll was good enough, of course.