How did the feeling of terror return to Douglas at Lake Wentworth ? How did he react ? ( DEEP WATER )

The feeling of terror returned to Douglas at Lake Wentworth when he was in the middle of the lake, put his head under the water and saw bottomless water. But, he overcame this fear by asking it sarcastically what it could do to him. This helped him face the challenge and overcome the terror. He continued his swim and managed to complete it successfully.