This play is of the scholar who comes before me. I continue from his grip and finish his play here, although other scholars will use his grip to make other plays. Watch what comes after and you will see their ways.
This play flows naturally and easily from the 1st scholar of the 9th master. Against a sottano stab, make the cover of the 9th master. Grab your opponents wrists with both hands, using a grip like you are holding a sword in two hands. Move the point of the dagger off line and rock your weight back slightly to give yourself more room to move. Slide your right hand back to grab the dagger blade as shown by the 1st scholar.
Sharply twist the dagger down and under your opponents hand. This will strip it from them. As you do so, keep pulling back with your left hand. Simultaneously shift all your weight forward, stepping through with your back foot and lunging into your opponent as shown.
You do not stab with the dagger exactly. Given your hold on the blade and the limited space, you would struggle to deliver a great deal of power into a thust like this. Rather, hold the blade quite close and brace the handle of the dagger against your body. You now effectively have a large spike extending from your chest and are running into your opponent to impale them on it.
To continue this play, if your opponent somehow manges to jam your delivery with their left hand, you can then use your own left hand to scoop over the top of both their arms, turning them in a clockwise direction. This will expose their back and the left side of their neck to a fendente stab. From here, you will have ample opportunity to follow up.