Whatever's in that pot is too distracting for Trico.
Here you'll see blue smoke billowing out of the structure to your right. Clamber inside and have a look around.
How to close the blue smoking pot
You'll see a smoking pot on a small train track and above that, a ledge and ladders rising up into a chimney. Pull the urn into the middle of the track so Trico sticks its head through the middle window.
Go back outside and climb on Trico's back, then jump to the vines and pull yourself up.
Head to the chimney and down it, then close the lid on the pot. Trico will remove its head and come back outside into the daylight and you can now continue on your journey.
Walk through the stone doorway and call Trico, who jumps up on wall. Next, climb his tail to his neck, and it will jump up and through a tight crevice into the next section.