Complex sentence: Assuming the worst, he goes to find Ivan's doctor, who tells him that the priest is in the garden-the bullet hit, and neatly removed, the tumour that had been going to kill him, leaving him in perfect health.
Split into simpler sentences: Assuming the worst, he goes to find Ivan's doctor, who tells him that the priest is in the garden. The bullet hit, and neatly removed, the tumour that had been going to kill him, leaving him in perfect health.