Read it through once

As I raised the blind, and the morning sunlight flooded the room, I heard the Professor’s low hiss of inspiration, and knowing its rarity, a deadly fear shot through my heart. As I passed over he moved back, and his exclamation of horror, “Gott in Himmel!” needed no enforcement from his agonised face. He raised his hand and pointed to the bed, and his iron face was drawn and ashen white. I felt my knees begin to tremble.