The swap went off without a hitch - now we can finally get our hands on the prism.
A good first step would be to get the actual key back from Nuri.
Yes, which is why you'll need to bring the boat back down to the ground.
Perfect; you can use it to get into the chest.
That was easier than expected - but you can't just walk past the guard with this thing glowing a hole in your pocket.
Try throwing it outside to collect later.
Well, not if you throw it into the water!
... Throwing it into the water will probably make it sink, though. Try finding something to stash it inside.
Something that would float in water, and still comfortably fit the prism inside of it.
You'll find something like that in Harm's cabin.
Grab the wooden box near the chest, then stash the prism inside it.
You can then throw it out of the window safely.
Geron can't swim - you need to find something that can drag the box over to you.
A fishing net would do the trick - dragging things out of water is its whole purpose.
They may be up to nefarious things, but smugglers are bound to keep some ordinary 'fishing stuff' around. Makes them look less suspicious.
Check out the smugglers' secret stash.
Grab the 'hammock' hanging between two poles in the smugglers' den.
You can then use it to retrieve the wooden box.
We have everything we need - the next step is to find safe passage into the swamps.