Whatever Cal had expected of the Sargasso Sea, this wasn't it. The ocean spread wide and blue under a cloudless sky, only the slightest of swell disturbing the water. She swayed instinctively as she sketched.

"What are you sketching?" Dr. Franklyn came up behind her. "There is nothing to see." His white eyebrows lifted.

"That's what I'm sketching." Cal didn't turn to look at him.

"What?"

"Nothing." She held the sketchbook so he could see, then put the ...