Bob mentioned his employee Doug flying over the forest - and if we want to access the employee-only areas of Bob's Interplanetary Saucer Shuttle Service, we should try to find him.
This is the low-spoiler guide for "On Doug's Trail" puzzle in Dexter Stardust: Adventures in Outer Space. 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.