Dr. Moller talks about the aids needed to bring the mare back in the corners, and then has her ride forward on the long sides to a halt in the corner.  The next step is to collect her in the corners rather than halt.  Dr. Moller has her work on the collected walk before asking for the canter depart and they continue with their work on the collected canter.  He explains that she can't hold the collection with her hands, but must do it with her body. . Her final challenge is canter with the reins in one hand while trying to touch her tail with the other!  It is interesting to see how the jump in the canter changes as she does this!