Finishing his meal, he leaves the tavern.

As he walks purposely forward toward the home of Christian Huygens, where he plans to discuss some recently formulated cosmological principles, his thoughts turn backward. Memories of his daughter have brought in their wake other recollections. On a sunny fall day in the Netherlands, he finds himself transported against his wishes back to a winter in Bavaria over twenty years before.

In a vivid daydream, he sees himself at twenty three, an unpaid volunteer, a tourist really, in a Protestant army organized to do battle against Spain and Austria. A lull in the campaign allows him to continue his various scientific investigations.

November, 1619. He spends the winter in a heated room near Ulm, Bavaria, on the road from Frankfurt to Vienna, near the Danube. He meets with the mathematician Johann Faulhaber. Embarks on an inventory of his knowledge; begins an accounting of what he has learned and what he still needs to know. Contemplates pulling down his old house to build anew, casting away the shifting earth and sand in search of bedrock.

November 10, 1619, a day filled with intellectual excitement. A fire, a light capable of dispelling even the deepest shadow, seizes his brain. He remains in his room all day. In his mental fever, he goes to bed.

The dreams begin.

He can still recall them as if he had just awoke.