Head up the windy tunnel

You're curiosity is fully piqued by the breeze from the side passage. If you're guesses are correct, a secondary exit would be useful thing to know the path towards.

"Hey Una, check this tunnel out."

Una looks questioning but promptly complies, walking up to the mouth of the indicated passage and leaning in. She takes a sniff, and straightens up from surprise and interest.

"Fresh air."

"Is it? Excellent. Think it could be a way out?"

"Thought you said you wanted claim bigger hoard."

"And I still do; if it does lead out we just turn right back around. I just think that the chance of cutting something like a mile out of our trip back might be a useful thing to know."

Una looks back at you for a long moment, then nods.

"Agreed."

She takes the lead as you head down the path, and you find yourself disinclined to cut around her as you watch her heavy ass shake with each step.

Una stops suddenly, unaware of how you barely avoid stumbling over her, and points above herself.

"Look."

You follow her gaze and see an interesting sight: the tunnel has no roof, the dome of the afternoon sky visible. You hadn't heard of an open air section of the caverns, perhaps you're closer to the heart of the labyrinth than you thought?

Suddenly a shadowy passes quickly over you and Una, startling you both.

"What was that?" Una hisses out anxiously.

"I couldn't tell."

A piercing screech pierced the air then.

"It's coming back!"

The two of you huddle low against the wall, and get a clear look at the flying thing as it passes overhead lower and slower.

A hunting griffon that just caught a giant rat.

You eye's grow wide at the sight. Griffons are majestic predators, a mixture of lion and giant eagle that is gifted with incredible strength. From what you remember, they usually live on top of cliffs and quarries, and have a hoarding habit similar to dragons, except they prefer to gather gem geodes over gold. Common lore claims that their eggs are a shiny, pale green that makes them resemble huge chunks of jade, which causes the adults to confuse ore deposits with abandoned nests. Whatever the reason, griffon nests filled with enormous gems are well documented, and the opportunity being presented is too great for you to pass up.

You watch as the griffon spirals down for a landing, then turn to Una, who is staring at the patch of sky it descended from with sheer terror.

"Think that you could lead us to wherever it landed?"

"Why would you want that!?!" She bursts out.

"Because griffons like to collect gemstones, and so do I."

"Tolin mad!" Is all Una is able to articulate at that, but thankfully she trusts your abilities enough to take off towards the beast.

It's a decent length trek down the slope you're on, but you reach an open expanse of flat rock, and seated on a wide outcropping is the griffon, greedily digging into its prey.

You watch the creature eat and try to choose the best course of action for stealing from it's nest:

You hate to admit it, but none of your spells are likely to be able to oneshot the griffon the way you did the ogre, at least not from this distance. Though they could likely drive it back, there's little way to tell for how long.

You could sneak closer for a better shot and hit, but there's no cover between the mouth of the maze tunnel and the griffon's nest.

You or Una could draw it off while the other raids the nest, but you don't like the idea of separating, let alone the danger of intentionally provoking the monster.

You could wait for it to fly off again, it seems to be alone, but you could be here for hours in that case, and you don't know what else is in these passages.

"Master'" Una pipes up, still watching the griffon fearfully, "What do we do?"