As Astra asks a nearby herald about the Griffon Cavalry, two winged creatures rush by overhead. The herald points up. “Looks like they’re already here!”

Rasa and Zeek make it about halfway to the cloud giant castle before they are intercepted by armored guards riding powerful griffons.

The lead rider, wearing the uniform of Waterdeep’s city guard, points and shouts at Rasa: "Descend NOW, by order of the Lady Silverhand! You are unauthorized for flight within the city limits." Their griffon mounts flap their wings to stay aloft, while holding their eagle-like heads proudly. The griffon riders are armed with long lances and crossbows.

Many more griffons begin to circle the skies between the floating castle and Waterdeep.

"Many apologies, mis amigos. I will descend at once, but please know that our interests are aligned. I am an esteemed member of the Emerald Enclave and I am traveling with a party of adventurers who are, how you say, working in opposition to this giant threat, yes? We are only here to help protect this city."

Persuasion Check: 17

The rider, who is obviously a guard of some rank, considers Rasa's words as the two of you float hundreds of feet above the city.

"Party of adventurers? Do you mean you and this winged housecat? To whom else do you refer?"

Genevieve grabs Astra's shoulder to get her attention, pointing up in the sky. "I think that Rasa found our Griffon Cavalry. It seems that birds of a feather do indeed flock together." Astra shrugs at that observation. "Well, it's certainly convenient."

"Yes, si. Me. This winged housecat. His master, Nirzeg. Lord Derrikoth Toknal of the Lord's Alliance. TWO members of the Harpers." He gestures to the streets below. "They don't all have wings but I can assure, mi amigo, we are quite the force. If you insist I fly down I will comply, pero it is a mistake not to have the extra hands at your service. Mis compañeros have seen the worst of what these giantfolks can do--in Triboar, for example, and further east into my territory. We are assets y we are here to help. We just don't all have wings, yes?"

The guard captain considers once more. "Triboar? Very well. Gods know we can use all the capable help we can get. With me then," he says to Rasa. 

Wheeling his mount around in the sky, he speaks quickly to his partner. "Sergeant. Fly down and find this Lord Derrikoth Toknal. Apparently he leads the band of adventurers that fought the giants in Triboar. If you can confirm this story, bring them with you."

Rallying half of the riders each, the captain and sergeant take divergent paths; one group climbs while the other descends to the streets.

"Lord Toknal!" The Griffon Cavalry sergeant calls out from the back of his griffon. The creature paces the streets near where Derrikoth and the others are. "Lord Toknal! Reveal yourself! I've been asked to speak with you."

If Rasa and Zeek continue to follow the cavalry, they will eventually find themselves near the entrance of the cloud giant castle. The massive structure rests on what appear to be two huge, solid clouds—the main castle rests on one cloud, and is connected by a high archway to what must be a gatehouse. As you fly higher, you notice many arrowslits and crenellations for defense. The castle exists of several levels, and is hundreds of feet tall.

The guard captain looks to Rasa. "Should we scout the top levels? Or try the gatehouse?"

Derrikoth looks up at the man shouting his name, "I am he. My associates and I require transport to that flying castle over there. Provide such, and I promise you that we will drive off those monsters and protect your city."

"Ah!" Obviously surprised at being addressed by a dragonborn, the human sergeant recovers. "I see," says he. "My name is Sergeant Agundar. I am to bring you and your giant-fighting companions to the castle in the sky. They won't get the drop on us like they did at Nightstone." 

Several griffon riders alight on the street nearby, following Agundar's signal. They assist each of you in climbing up onto their mount, and instruct you to hold on tight.

// Do you all mount up with the riders? //

Derrikoth nods solemnly to the guard before hopping on a griffon.

Astra and Genevieve climb on their Griffons.

Nirzeg, who having decided to casually lounge on the rooftop after speaking his piece, sighs heavily if/when a griffon rider decides to land nearby him at least. After a brief moment debating on whether or not to pretend to not understand any of the words or gestures, he flips back onto his feet, dusts himself off, and with a final and mildly annoyed look shot in the direction of the group, hops on board as well.

"I do oh so hope there's a sizeable reward for services rendered today." He comments on idly. Meanwhile, an increasingly more nervous Zeek continues to follow Rasa wherever he goes, but not without meowling complaint at least once along the way for all the back and forth.

The world falls away from you as the griffons climb higher and higher into the sky. (No one is afraid of heights, are they?)

(The castle essentially looks like this, as portrayed. The gatehouse is on the smaller cloud to the right of the image)

The Griffon Cavalry, wary, begins to scout around the perimeter from very far away. It's hard to make out most of the details, but there seem to be many open areas of the cloud giant castle. The main entrance at the gatehouse may be just a formality, especially for flying creatures, but it's up to you—do you encourage the Griffon Cavalry to enter through the front door, or try and land directly somewhere on the castle "grounds"? 

Astra will suggest entering through the front door. "If they wanted to keep us out, I imagine that they would have shot us all down by now."

"Hah! More likely it is that they couldn't give two shits about a bunch of birds flapping about, so long as we don't stain their precious buildings." Nirzeg comments on, following a brief internal debate on the likely nature of the giants. "Either which way, they haven't done anything... YET. So, it's only polite we 'try' to be reasonable, and go through the front. Though you riders are gonna want to take off once we land, and keep on the look out. Or at least be at the ready for when we need'ja!" He calls out over the wind to the others. But as soon as there might be an opportunity for it, Zeek sneaks off to explore one of the larger off-shoot areas besides the guard towers, using all the powers sneaky cat that he is.

The Griffon Cavalry drops you off on the front of the cloud. The “terrain” here is hard cloud-stuff; there is not a blade of grass or a patch of dirt inside. 

Built atop this smaller cloud, and connected to the main keep by a stone bridge, the gatehouse stands ready to accept you. 

A bald, gray-skinned giant in an ostentatious toga opens the door to you. In his arms he holds a hippogriff like a pet cat.

<Ah! Stratus did hear something after all. What business have you here, small ones?> The lanky gray giant booms in his native language. <Do you have an appointment?>

In giant: "I fear not. Your beautiful castle arrived rather suddenly, so we would not have had time for such formalities. If you would excuse our intrusion and answer a simple inquiry: what is it you are doing here? And may we converse in the common tongue for the benefit of my friends here?"

The stoney-skinned giant scratches his head. “Uh...yes. You...follow?” His Common is exceptionally broken, and he uses his fingers to mime the act of walking behind him. 

He sets off at a generous stride down the high-arched bridge towards the keep, allowing the hippogriff to fly free. It circles round, but warily eyes the griffons overhead. The hippogriff stays low and very close to its giant friend.

 The giant motions, expecting you to follow him.

Rasa will nod to his companions and then take off, flying after the giant.

"Loud as always." Nirzeg comments  dismally under-breathe. And yet for all of his bubbling up cynicism, he kept the worst to himself as he followed along after Ah'braser and the rest. Though, in keeping in mind everyone's position, he tried to be off enough to the side to avoid any linear "unkindness" directed the groups way; even if that meant some extra attention from the hippogriff... if it ever to curious.

"Oi! This one Nirzeg. One is your name?" He calls up to the giant as he pulls out Volo's Guide in readiness to study up.

"Steinnros," the giant rumbles in response to Nirzeg.

The door at the end of the bridge (the main entrance to the keep) is decorated with ornate griffon and hippogriff bas-reliefs. The creatures are sculpted in such a way that has them frolicking among clouds. It looks surprisingly welcoming.

The door is guarded by two tough-looking, gray, bald giants in togas, like the first one you encountered. The guards' togas aren't quite as ostentatious as the first. The giant guards stand aside as you pass.

If you continue to follow the giant, he will lead you through the main doors and to the right, into a gallery full of treasures. Ornate masks, statues, ancient tomes and scrolls, paintings, and ceremonial weapons are all displayed prominently here, like a gallery. The ceiling soars above your heads, 40 feet tall at least. 

"You...wait...here," says the giant. In jotun, he finishes, <Don't touch anything.>