The balloon was red and utterly opaque. Blum looked like he was wearing a hastily made Halloween costume. A pencil with a bright red eraser? The main character from The Red Balloon?

Unable to see, he waved his hands around until he bumped into the tank. He climbed over the side and lay down in the water. His big balloon face on a skinny body. Within seconds, he sat up and yanked the balloon off, water pouring out. After catching his breath, he tried again, rolling it back on and, this time, tying a string around his neck to reduce the water infiltration (a nice additional touch for The Red Balloon costume). After a few minutes of fiddling and experimentation, Blum announced, muffled from inside the balloon, that he thought this would work. He could always thump on the sides of the tank for help if he needed it. He lay down in the water.

All three of them paused, unwilling to close the top of the tank. Tibbet and Eh had their faces slightly averted, as though this pained them. It was apparent how different Blum was from them. He floated on his side in the warm water, fetal position, a baby with a swollen rubber head. He seemed relaxed, his limbs loose. His rib cage of a plucked chicken, the bag of air around his head, the hissing of the hose.

In this moment, both his strength and fragility were vividly displayed. His body, like his ideas, was floating there risky and unlikely, tethered loosely to safety. At any moment there might be a puncture and his career could whistle away.

Eh lowered the cover on the tank. All three of them sat there for the twenty minutes, Eh chain-smoking, before Blum thumped on the side of the tank to get out. He was grinning, thrilled, with a few modifications to make to the apparatus.

The other Harvard researcher, Timothy Leary, would visit in a few days.

* * *

By the end of the second week, Cora could blow the whistle and hold up the circle, square or triangle and the dolphins would tap the matching shape stapled to the dock over 90 percent of the time. Each time they got it right, she threw them fish as a reward.

Now that the training was complete, Tibbet and Cora began the active part of the experiment. She set up a collapsible pen on the far side of the lagoon, stepped inside and called Junior into it. She rubbed his back to thank him for obeying and nodded to Tibbet that she was ready. He stood on the dock, above the shapes stapled to the end of it, the other dolphins watching him. This time, when he blew the whistle, he did not hold up any shape. Instead, Cora (inside the pen, her back to the others so they could not see) showed the black circle to Junior.

Junior, in the pen, could not get to the dock to tap the matching black circle. The other dolphins by the dock could not see the black circle to know which shape to tap. The point of the research was to find out if the dolphin in the pen could somehow communicate the correct answer to the dolphins across the lagoon.