Carlata gave Henry his sketchbook. There are nine slots to fill with drawings from interesting relics you find around.
Just use the sketchbook on a relic to make Henry draw it. For example you can draw the Giant Head from the passageway north from the village.
Speak to Clayton, first.
This is the low-spoiler guide for "The sketchbook" puzzle in Mutropolis. Unlike in normal walkthrough, you get gradual hints on how to solve the puzzle. Click the big button below to see your first hint. If the hint contains a spoiler, you will be warned about it before clicking.