Five dark shadows hustled along a low-lit corridor on the planet of Kantal-ka. Dressed in all black and outfitted with sleek weapons and cleverly disguised spy gear, the five princesses of the Pentangle felt very removed from their former posh lives.

"Psst," Rhea hissed from the back of the line as she and the other girls raced around a corner. "Luna! Can you tie your hair back or something? It's huge — there's no way Geela's security cameras aren't going to spot it. It's almost big enough to warrant a few of its own moons." Luna spun around and glared at Rhea — her hair spun with her. Rhea grinned and wiggled a few fingers in a wave.

Luna's long blond hair was her most prized accessory. She had spent several hours deep conditioning and blow-drying it that morning, to prepare for SPACEPOP's show that night. It had taken days and gallons of expensive creams and tonics, but Luna had finally managed to wash away all remnants of Solar Glow. After weeks of suffering through bad hair days, Luna's locks now looked better than ever. "My hair is a lot less noticeable than your constant yammering and bad jokes," Luna snapped back.

"Can we all just focus on the mission?" Athena asked, shushing them both. "We need to finish our exploration of Kantal-ka, then get out of here. In case anyone has forgotten, according to the information Captain Hansome sent over this morning, Geela's troops are scheduled to return from their training session in fifteen minutes. And tonight's gig starts in less than two hours. We need to wrap up this search and get out of here. We have another job to get to."

The five girls paused when they reached a T in the corridor. Straight ahead of them stood an imposing, glossy black wall. To their left was a giant archway, leading out into the blue-purple Kantal-ka night; to their right, a closed door. There was no sign of life in either direction. "Which way?" Hera asked, glancing at the others. Without waiting for an answer, she closed her eyes and hummed. "I'm trying to visualize the correct path," Hera said in a moony voice. "I'm getting a definite left vibe. The night sky is calling to me, telling me we all need to step outside and recharge before moving on."

"Then let's go right," Juno said, moving toward the closed door in the opposite direction. "We don't need to recharge. If we want this mission to be successful, we need to explore every possible wing of Geela's facility here on Kantal-ka. Otherwise, we might miss something that could lead us to our parents. And who knows when we might get back to this planet again."

"Juno's right," Athena agreed. "We need to see what's behind that closed door."

"Behind Door Number One ..." Rhea said in a funny game show announcer voice. "A new space transport!"

Luna flipped her enormous hair over her shoulder and shushed Rhea. Then the five princesses slipped around the corner and made their way toward the mysterious closed door.

On orders from Resistance leader Captain Hansome, Rhea, Luna, Athena, Hera, and Juno had been exploring Geela's central command station on Kantal-ka for just short of four hours. During that time, they had found no evidence that Geela's Dungeon of Dark Doom was hidden away on the foggy planet of Kantal-ka. But it seemed that every time they thought they had reached the end of the facility, there were more doors leading into unexplored turf.

Athena reached out to press a button, and the closed door whooshed open. They all slipped through the door and waited as it closed behind them. Ahead of them stretched another long, empty corridor that led to yet another door. The girls raced down the corridor, pressed another button, and this door slid open. On the other side of this door was yet another long corridor with yet another door at the far end. The girls carried on. And on. And on.

"What's with all the doors?" Rhea asked after they had passed through the sixth identical door. "Think Geela's just really into climate control or something?"

Juno narrowed her eyes. When she was a contestant on Fight or Flight, she had faced a maze of doors and hallways that felt eerily similar to the one they were in now. Her stomach clenched into a fist and she muttered, "I hope it's not some kind of trap. These doors must be protecting something."

Rhea scanned the smooth walls, searching for security cameras or any other indication that someone might be watching their every move in some far-off control room. She couldn't find any signs of enhanced security or tracking devices, which made her think they were on a wild-goose chase. "Has anyone else considered the fact that none of these doors are locked? And we haven't seen a single guard or one of Geela's Android Soldiers all day. If the Dungeon of Dark Doom was hidden somewhere in this facility on Kantal-ka, don't you think it would be better protected?"

The other girls nodded their agreement. But until they were absolutely sure they had hit a dead end, none of them was willing to call off the search. Because when — if? — they found Geela's Dungeon of Dark Doom, the girls were sure they would also find their imprisoned parents. That singular goal was propelling them all forward, giving them strength to carry on with their difficult and dangerous Resistance mission. If they could find the secret location of Geela's Dungeon of Dark Doom, they would be able to release their parents, thus allowing the Pentangle Galaxy — and its princesses — to go back to life as usual.

Thanks to intelligence the girls had helped gather on one of their first assignments for the Resistance (the SPACEPOP crew planted trackers on Geela's entire fleet of space tankers), Captain Hansome and his team had been able to figure out that Geela and her army spent the majority of their time and resources on five planets — Kantal-ka, Lud, Pallomo, Tik-tik, and Pluton. By using the tracker data the disguised princesses had helped to collect, Resistance forces decided to turn their attention to these five planets to see if they could figure out how to weaken Geela's strongholds.

When Hansome told the girls about the team's findings, Athena was the one who pointed out that it would also make sense to narrow the search for the missing royal families to those five planets. Geela was the kind of leader who would enjoy visiting her prisoners regularly, relishing in their discomfort and weakness. She wouldn't be likely to hide the Dungeon of Dark Doom anywhere that would be too hard for her to reach or too remote for her to visit regularly. Therefore, if Resistance forces were to conduct an extensive search of each of the five planets Geela spent most of her time on, they would very likely find the hidden Dungeon of Dark Doom and the royal prisoners.

The trouble was, each of the five planets the Resistance forces needed to search was in strict lockdown mode. All travel onto and off each of the planets was restricted, and the only way anyone was allowed in the planets' airspace was with a valid travel authorization. Anyone caught entering or leaving without said authorization would be destroyed without question. So it wasn't as simple as dispersing Resistance forces to search each planet in a hurry — no one could land on any of these planets to start the hunt.

When Captain Hansome had delivered the bad news, Luna shrugged. "So we use our cover as SPACEPOP...