I search my head for some advice from Imaginary Mike Hammerhead.

“I have nothing, kid, you’re on your own.”

Thanks, Imaginary Mike. That really helps!

I swim slowly around Rick, scratching my hammer in total frustration.

Rick floats motionless in the performance pool, nose down.

I think I see a tear in his eye.

Rick quickly fins it away, and any sign of weakness is gone.

“You got us into this,” he says with a low-down snarly growl. “You get us out!”

There’s no point telling him that I wouldn’t be here at all if it wasn’t for him swimming away from home to join the sea-circus, and me finding his stupid jacket and coming to save him.

There’s no point telling him but it doesn’t stop me thinking it.

I widen my circle.

Come on Imaginary Mike Hammerhead, Shark Detective, you’ve been in tighter spots than this. Help me out, here! I search my brain for ideas but all I get is:

“……….. …………… ……………………….. ……………………………….. ……………….”

I guess I really am on my own.

Ping!

What?

Ping! Ping! Pinnnnnnnngg!!!!!

My hammer-vision has suddenly turned itself on. Now, this only happens for a very small number of reasons.

There’s food nearby.

There’s danger nearby.

That’s it.

There’s certainly no food in the performance pool and Rick is not my idea of lunch, so it must be danger.

I narrow my eyes. It’s time for Harry Hammer to become Harry Hammer, Shark Detective for real. No more Mr. Nice Shark.

I scan the immediate area with my hammer-vision on maximum.

Danger can come in many forms. I can see that only Rick and I are in the pool. So it can’t be any leggy air-breathers. It must be something else.

I swim down, and my hammer-vision starts going crazy.

Ping ping hiss ping ping ping!!!!!

The pings are dragging my hammer around toward the wall of the pool. The hiss ping narrows it down. I swim over, not knowing what to expect.

“What are you doing, kelp breath?” Rick calls to me.

I ignore him.

Harry Hammer, Shark Detective is on the case.

I reach the wall and start up hammer-vision-scan-mode-ultra. The wall zooms into sharp focus.

“In the mean performance pool,” I drawl to myself like Mike Hammerhead, “you have to pay the closest of attention. Every clue counts.”

Yes!

There!

Right where the wall turns a corner to head back toward the shore, is a crack that I didn’t notice before. It’s not a big crack, but it is slowly bulging out from the weight of the water it’s holding in the pool.

I swim closer.

Where the tide has gone out beyond the shore, there’s no longer equal pressure from sea to hold it up. The whole thing is in danger of collapsing!

I tap it with my hammer.

Nothing.

I thud it with my hammer.

Ping ping ping hisssssssssssssssssssssssssssss!!!!

The crack splits a little farther up the wall. . . .

I swim back to Rick, my heart pounding with excitement. This time I don’t hug him. But I do whisper in his ear.

“Rick. I have another plan!”

Minutes later we’re putting on the best show the leggy air-breathers have ever seen!! And if my new plan works, they’ll never see anything like it ever again!! Or at least they better not.

I pull a three-sixty hammer-dart and tail-rush down to the weak spot in the wall.

The crowd cheers and goes wild. Their excited yelling and clapping completely covers up the sound of me thumping my hammer at full speed on to the crack!

Tssssskkkkkk! (That’s the crack, cracking open a little bit more!)

Rick runs a shallow-half-wave-roll-flip and plunges down.

Cheers!!! Yells!!!! Applause!!!!!!

Thump!!!! Rick bangs the crack with his nose.

TsssSSSSSSSSSsskkkkkk!!!!! It opens up a little more.

I drop a totally awesome seven-tail and Acrosprat devil-dive and thump the crack with my hammer.