They do, and find out what's happening!

"Okay then," the boss of the Villains stated as he paced around the room, before his eyes found David and Sam. "You two, up on your feet. You're going to the top floor to get something for us."

"And if I refuse?" David asked, gritting his teeth and clenching his fists.

"Then somewhere on this island, you'll hear the screams of a particular pretty blonde girl," the Villain replied with a smirk. David had to resist the urge to punch the man. This hadn't been the plan, and he'd told Sam to call it off anyway! And given that Sam was acting regardless, it was likely that these weren't the fake Villains they had agreed to use. "Come on, get moving, and don't even think of getting cold feet!"

As David and Sam were escorted to the elevator, which the Villains could control, All Might tested the tensile strength of his bindings as subtly as he could manage. Breakable, but not without enough strain that it would instantly alert the Villains unless they were distracted. Damn. He hoped David stated safe... He then paused as he noticed some flashing out of the corner of his eye.

He turned his gaze upwards, towards the glass ceiling, and spotted Midoriya behind a railing on the floor above, using the flashlight feature on his phone to signal him. Izuku then gestured to Kyoka, who knelt nearby, her jacks to the floor. "...hope you can hear me..." All Might muttered, before explaining the situation quietly. "...you have to escape this tower, and tell the Heroes outside what's happening..." he concluded. He was gratified to see Kyoka withdraw her jacks, and immediately talk frantically to Izuku. Good, she'd heard him.

...

"This is bad," Setsuna paced once everything was explained, and they hid in a nearby dark room.

"Gee, you think?" Itsuka asked Setsuna blandly.

"We need to follow All Might's instructions. Get out of this tower, and find help," Iida stated.

"But that's much easier said than done," Melissa replied, a hand on her chin. "The security here rivals that of Tartarus, the most max security prison in the world. Getting out will be next to impossible."

"So I guess we just sit tight then? Wait for everything to blow over?" Mina suggested.

"Like hell," Izuku shivered, barely contained rage in his eyes.

"...Izuku?" Momo asked.

"My Mom's down there," Izuku reminded them. "And not just her, but a lot of other people who need our help. We have to do something!" he asserted.

"Whoah, calm down man, we gotta look at the facts!" Kaminari waved his hands.

"Yeah, these guys have even All Might taken hostage, what can WE do?" Mineta asked.

"I don't know, but we need to do something! If we can just get the security system back under control, we can put a stop to these Villains!" Izuku declared.

"How would we even do that?" Todoroki questioned.

"I could try hacking into it!" Mei suggested eagerly, but Melissa shook her head.

"If you did, you'd run the risk of alerting them to the breach, even if you could pull it off from here... But at the top of this tower is the central control room for the system," she mused.

"That's perfect," Izuku nodded. "We just need to get up there, and reset the security system, and then All Might and the other Heroes will be able to spring into action, and save everyone!"

"This is an incredibly risky idea!" Iida protested. "We're not even licensed and allowed to fight the Villains!"

"First of all, this is I-Island. The Quirk use laws are at least a little looser. We shouldn't get in trouble, even if we do have to fight!" Izuku pointed out. "But just to play it safe, we'll try to avoid fighting, stay under the radar, and head upstairs to get into the control room!"

"But the Villains are likely to have several of their number gathered there," Todoroki pointed out.

"Yes, but Tooru can sneak us in once we're up there," Ochaco suggested. "She can render us invisible so long as she maintains contact! If we can slip in unnoticed."

"Hey, great idea, ribbit!" Tsuyu nodded.