Plate

Enemy sword raised for mandritto to the head; fencer already extended in Fourth guard, point arriving before the cut falls
Enemy sword raised for mandritto to the head; fencer already extended in Fourth guard, point arriving before the cut falls De lo Schermo, overo Scienza d'Arme · Copenhagen, 1606 · Plate 26

Translation

The following is a wound in Fourth against a sword raised in the air. It proceeds from both being on the outside, and from the striker having gone to find the enemy sword, which could easily have been in Third or in Second. While that sword was rising to strike a mandritto at the head, the striker, already in motion with Fourth as he went to find that sword, did nothing but extend his own sword and advance the right foot, so that he arrived before the other fell.

Even if that cut had fallen, it would have done nothing, because in extending he had raised the hand enough to cover the head, thereby defending himself from the cut. And that cut, because it was made from the elbow, is very open and slow in wounding; this is what produced the present wound. Had the said cut been made with the wrist, then in the time that the striker wounded, the sword would have fallen onto the one that was wounding, so that in the figure one would see defense and offense together. Since it happened otherwise, here one sees only the offense.

Analysis

Initial guards Both outside; enemy sword may be in Third or Second.
Wound Thrust in Fourth (quarta).
  1. You go to find the enemy blade outside (andato a trovare la spada nimica).
  2. The enemy raises to strike mandritto to the head (si levava per ferire di mandiritto per testa).
  3. You were already moving in quarta.
  4. You simply extend and advance the right foot (slongare la sua inanzi, avanzare il destro piede).
  5. You arrive before his cut falls.
  6. Even if the cut fell, your raised hand would protect the head.

Translation note

Not merely "against a sword in the air." Better: "against a sword raised to strike mandritto."
The Steel Marginalia · HEMA Study Group Notes in the margins. Truth in the bind.