Jack had been right, she decided – remaining on the back of a galloping horse without benefit of saddle was a question of balance, and of anticipating the horse's movements, while also relying on some cooperation from the horse! Soon Vla began to sweat, which made her slippery, and then Eliza had to abandon all pretense of holding on by brute force and rely entirely on a very complicated and ever-changing sort of sympathy between her and the mare.