"Brain, run this past me again?" The following morning, in Chief Quimby's office, Inspector Gadget scratched his head. "What do you mean, Penny's gone into the whirlpool?"

The Chief was looking red-faced and angry.

"I told her she was off the case! Now she's in as much danger as Talon!"

Gadget was halfway to the door, and Brain ran behind. The Chief yelled after them.

"The Professor's already on his way..."

When they got to Metro City Baths, they found Jade and Professor Von Slickstein waiting for them.

In the bottom of the swimming pool was an amazing new vehicle. It looked like a cross between the Gadgetmobile and a nuclear submarine. It had radar aerials and flashing blue lights and a huge control deck at the front, with furry dice hanging above. The Professor was polishing one of the portholes as Gadget and Brain clambered down into the empty pool.

"I've been waiting for a chance to use this... it's a new addition to our fleet. The Gadgetmarine! I've got it ready for the climate crisis, just in case."

Gadget and Brain were already climbing aboard. They mounted a ladder to the hatch, then another ladder led them down into the cosy interior with its leather seats and storage bays and big, red-topped levers. The Professor climbed inside to join them, and found Jade coming too.

"This is really for HQ personnel, only..."

"Forget it, Prof." Jade took a seat. "I'm coming to find Gareth, and those kids. Plus Penny and Talon. I've worked around water longer than any of you." She held up a bag. "I've brought a picnic from the cafe, too."

When everyone was ready, Jade rang main reception at the Baths and told them to let some water back into the pool, just enough to make the submarine float. The Professor took the controls. There was a sound more like a car engine as he turned the ignition key. Then they were heading towards the deep end, and the whirlpool.

"Brace yourselves!" the Professor called. "Here we go!"

They were all sent reeling as the Gadgetmarine hit the whirlpool with an almighty shudder. Then, just as suddenly, they were under the sea, with every form of marine life swimming past the portholes. Gadget looked out.

"Wowsers! This is a very large fish tank."

There was a beep from the radar. The Professor looked down at a glass viewing panel built into the floor of the sub. He saw Penny's arrow.

"Look! Penny must have left that. It shows we're on the right track."

They drove on.

"Whoa!" Jade had her nose pressed to a porthole, as excited as a little girl. "This is awesome. I swam with dolphins, and scuba-dived, but never this deep. Where are we?"

"Somewhere beneath the Atlantic Ocean, I believe." The Professor checked some readouts. "I'd better activate the shark detector."

He flicked a switch. There was another beep from the radar. Brain yelped. Gadget came to have a look.

"Sharks?"

"No..." The Professor looked at the radar screen. "That's odd. It's detecting another human presence... several! I'd better activate the Concealment Function."

"Concealment?" Jade still sounded excited. "Hey, is that like that movie... the invisible car?"

"An invisible car? How ridiculous." The Professor adjusted some more controls. "An invisible submarine, however, is perfectly feasible."

Close to the seabed now, the Gadgetmarine faded from view. Then, several people came swimming past, with virtual scuba kits similar to Penny's. There were several big, burly men and women, in purple uniforms and hoods. They looked similar to the old MAD uniform, but had a new logo on the front showing a pair of pincers. They also had larger and more powerful versions of the Gum Gun Talon had once used, with waterproof shields.

Swimming along at gunpoint were several children and adults, all looking frightened and unhappy. Still at the portholes, Jade leapt up.

"It's Gareth!"

"Easy, easy!" The Professor fought to control the vessel. "You'll have this thing over."

He activated a viewer screen, giving a better view of what was going on outside. Nearby, more Pincer agents were running a sort of supply station. The kidnapped and kidnappers were swimming towards tables built from rocks and debris upon the seabed. The children and young adults were being given pickaxes and shovels and even sticks of dynamite. They looked terrified – but faced with more Gum Guns, they obeyed.

One of the agents spoke into a loudhailer mask.

"OK, you lot. We're going on a little treasure-hunt. Do exactly as you're told, and no one will get hurt or sticky. Agents Four and Five will lead you on to Atlantis."

"Atlantis?" shouted everyone on the Gadgetmarine. Gadget shushed them and they went on listening.

"Anyone try any tricks, we turn your forcefield off. You'll drown inside two minutes. Now – move! Miss Pincer's waiting for ya."

The terrified troop took its equipment. With great difficulty, they swam on.

"It is the Pincer Movement!" Gadget said. "The Claws' cousins!"

"Gareth..." Jade gulped. "And the kids... hey, let's get after 'em!"

There was no one still outside. The Professor cancelled the Concealment Function, and Gadget activated the siren.

With flashing blue light, the Gadgetmobile tore on towards Atlantis.

Meanwhile, in the guest room, Penny was awoken by droplets of water falling on her face. She stirred, muttered in her sleep.

"Don't turn the shower on yet, Talon, I'm still asleep."

Suddenly she was awake, sitting up in bed. The whole room was awash. She saw the bedside table floating past her... then water pouring in from above. She borrowed her uncle's phrase.

"Wowsers!"

She ran across and tried the door. It was locked, electronically. She was still wearing her Codex bracelet. Thankfully, it was dry. It took her a good three minutes to hack the locking system... and all the while, the water was getting higher and higher...

Wet to the ankles, Penny shot out into the living area, and sealed the door shut again. She found the door panel James had used, and examined it. She worked out how to close the roof panels. The bedroom was sealed. Penny's eyes narrowed.

"Drown me, would you, Double-0-Nothing? Right..."

Now she was fully awake, she remembered their conversation after supper. Just what had James Pond wanted to hide from her?

Penny went straight to the bureau and took the parchment from the drawer.

She saw an ancient map of the seabed... the area leading towards Atlantis. In the heart of the city, an area was marked with a red cross. Penny knew a treasure map when she saw one.

She read the heading.

The Lost Treasure of Atlantis...

"Smart move, Miss Gadget," said a voice. "Now, lower that map, and turn around slowly. There's a Water PPE pointing at you."

Penny did as she was told. She saw James Pond covering her with a deadly water pistol.

"So that's what this is about! You're after the treasure! That's why you needed people!"

"I never did like girls with brains." James raised the PPE. "Back away slowly, against that wall."

Penny moved back towards the wall of the guest room. She was nearing the control panel again. She had one chance...

With one swift movement, she grabbed the panel and hit the buttons. James was taken by surprise, as the roof panels opened above him. He was drenched as water flooded into the room. His wig floated across the apartment like a drowning weasel. The sexy spy suddenly looked a lot older.

Penny already had the map inside her jacket. She brought her hands upwards, splashing seawater into James's face. His hands came up, dropping the pistol.

Penny was out of there in seconds, into the elevator, heading for the surface.

She swam with all her might, towards Atlantis.