Bahram Shoots Kabuda in the Dark

From B12.16, Bahram Captures Kabuda. It illustrates B12.16.14–18:

B12.16.14
Kabuda’s charger suddenly gave cry,Bahram stood still and heard the sound nearby.
B12.16.15
He strung his bow and mounted with all speed,Then pressed ahead upon his charging steed.
B12.16.16
Without a word he loosed an arrow straight,Though darkness hid the horseman’s form and gait.
B12.16.17
The shaft struck hard against Kabuda’s belt;His face turned black; he fell, cried zanhar, and knelt.
B12.16.18
Then Bahram said, “Speak truth: who sent you here?Whom would you have slain? Make your purpose clear.”