I tell them about Ester’s warning from last night. “So if this is the challenge, and we don’t respond, that will not be good. Either way, we need to decipher the code. Then we can decide what to do.”

My housemates visibly relax. Deciphering a code…that is a challenge we can tackle. It’s what Dolphins train for.

“Let’s assume the first part is blue whale.” Jack whips out his pencil and notepad. He starts sketching the purple blobs and waves. He says he thinks better when he’s working by hand, and since he’s our best codebreaker, I never argue. “That second part, with the clicks…Can we slow that down?”

“Uh…” I’m no Cephalopod, but after a few minutes of tinkering, I manage to replay the transmission at one-quarter speed, which makes the pattern clear. “That’s five by five.”

I don’t realize Gem is standing behind me until he asks, “What’s five by five?”

I almost jump out of my socks. Seriously, I’m going to have to put bells on his holsters so he can’t sneak up on me like that.

“It’s like Morse code,” I explain. “But different. In the Vietnam War, prisoners of war used it to tap out messages to one another.”

“And the third section,” Halimah says. “What is that?”

We gather around the map table and play the recording over and over at different speeds. Jack fills his notebook with sketches and mathematical equations. Halimah and Virgil argue about phonetic versus alphabetic symbology. Lee-Ann lectures us on the relationship between acoustics and fluid dynamics. It’s basically a giant Dolphin nerd fest.

I don’t realize how much time has passed until Gem sets a tray of sandwiches in front of us. “Lunch.”

While the others eat, I take a bathroom break. I freshen up, splash water on my face, take more medicine. My gut pain is now competing with back pain from being hunched over for so long, looking at codes. I consider throwing up but suppress the impulse by sheer force of will. Once I give in to nausea, the vomit genie is not easy to put back in the bottle.

On the way to the bridge, I freeze in my tracks. Suddenly, all the pieces of code that have been swirling around in my brain fall into a perfect pattern. I live for these moments. They’re as exhilarating as cliff-diving, and they’re the main reason I love being a Dolphin. Jack’s a better cryptographer. Halimah is more gifted at navigation. Lee-Ann has a stronger grasp of counterespionage, and Virgil is our expert at electronic communications. But I’m the best at putting all the pieces together to make a bigger picture. That’s why I was elected the freshman prefect.

With a grin on my face, I march back to the bridge. “I’ve got it.”