Soot: Go to the classroom. Examine the oven left of the alchemy corner.

Alchemy corner: Look at the alchemy corner. It is the perfect spot to make the magic ink.

Crocodile tears: See a bottle of dried crocodile tears in the flask. We need 2 cl of tears.

Jump to inn. Exit and see a bucket of water (melted by the heat) beside the fireplace.

Use the small glass marked 2 cl that is used by Rémi on the bucket of water. Get 2 cl glass with water.

Mix the ingredients: Go to the alchemy corner in the classroom.

Use the flask of dragon sweat on the pot.

Use the 2 cl glass with water on the dried up crocodile tears in the flask at bottom of screen. Add crocodile tears to the pot.

Look at the weight in the slot of the scale at left. Set the 3 Seastone ounces weight on the left pan.

Right click the chocolate in inventory to see that it is 2 Seastone ounces. Place the chocolate on the right pan.

Add soot on right pan until the scale balances and get one ounce of soot. Place the soot into the pot.

Mix the magic ink.