Commentary
This play is possibly connected to the previous one - it shows us a different way, in which you can besiege quinta custodia, preventing the notorius in-tempo counterattacks. It uses a very rare and very good siege.
This siege tries to trigger the in-tempo counterattack from the defender, while keeping options to deal with it. The text of the play seems to describe an action similar to "exchange of thrusts" from Fiore - the defender will thrust, but the attacker will thrust at the same time and prevail. This exchange might be happening under the shields of both fencers.
On the other hand, the last image is showing a stichslack, that theoretically also can defend the counterthrust. But no stichslack is mentioned in the text.
If the defender launches halpschilt counterattack instead of a thrust, the text says that attacker will fall under the sword and shield.
This play is interesting in that it uses in-tempo counterattack against in-tempo counterattack. The defender is ready to launch his in-tempo counterattack. The attacker tries to trigger it by shield strike, and if he is successful, he will use an in-tempo counterattack of his own.