“Don’t make me wish I was wearing a foil hat,” I warned her. “Look, the crewman has to go, because he knows how to drive the little sub, and Dr. Akana has to go because she knows what the heck we’ll be looking at, and I have to go because (a) I’m the leader, right? And (b) it’s my mom we’re looking for, and (c) because I said so. You dig?”

I crossed my arms too and frowned down at her, something that’s always worked in the past, but I doubted it would for much longer.

“Angel, dear, you’re only six,” Dr. Akana said kindly.

“Seven,” Angel said obstinately.

“When did you turn seven? Oh, never mind,” I said, getting exasperated. None of us knows when our actual birthdays are, so we each made up one for ourselves. Years ago I’d had to put my foot down about getting only one birthday a year, because Gazzy was trying to capitalize on presents. But, actually, we don’t really keep track of them too well.

“I’m seven.” Angel looked like a bulldozer wouldn’t budge her.

“Fine, then, I’m — seventeen!” I said. “You’re not going.”

The little sub in question was a three-person thingy that looked kind of like a large pool float with a bubble on top. It could go down to one hundred meters (about three hundred feet — our Big Daddy sub could go down about one thousand meters), and I practically expected to see foot pedals sticking out the bottom.

The only reason I was willing to get in it was because of the Plexiglas dome on top that you could see out of. Our current sub had no windows. I repeat, no windows. Zero. Zip. Nada. That was because the space between the outer hull and the inner hull was full of water when the sub submerged and full of air when it surfaced. A window would have had to have been about a foot thick. Instead, the crew viewed the outside on little TV screens, from cameras located on the sub’s exterior.

But now I had a chance to be in a big bubble and see what was going on. Anything would be better than being stuck in here.

I rubbed my hands together. “Let’s do it.”

Ten minutes later, a bottom hatch slowly opened, and we dropped down into the deep ocean. There wasn’t much light, but because the water around Hawaii is so clear, it wasn’t totally pitch dark, even at sixty meters deep.

Then the crewman turned on the headlights. It was amazing — our own underwater show. Above us was the enormous U.S.S. Minnesota. We were chugging out from under it, thank God. But the fish! There were fish everywhere, all sizes, moving slowly through the water.

“That’s a yellowfin tuna,” said Dr. Akana. “They can grow to more than seven feet long.”