The events of Holy Week are most clearly described in the Gospel According to Mark. And Mark doesn't have anything to say about Wednesday of the week.
So on this silent day, we can take the time to reflect quietly on the whole barrage of activity on the other days. We do well to sit in the uncomfortable feeling of the impending doom for Jesus. We can reflect on our own failure to trust him and live in his power.
I realized just today that I need extra time these days just to sit and soak in the presence of Jesus. He helps me to be present and to listen to truth.