Share the information received from Garlef with Baby Goal. Excited, the woman will run to the rebels' base - follow her (enter the dark alley seen from the market). Knock on the door. Unfortunately, the music from the marketplace will distract Rufus. Enter the options menu and lower the music volume to minimum, and knock again. This time, the guard will ask for the old code. Try to knock again, but the sequence will be incorrect. The guard will get angry, so hide in the crate next to the door and wait. The man will go outside, and to enter again, he will have to knock, using the old code. Leave the crate and knock - you'll be let in.
Click on the eighth puzzle fragment (on the floor, next to the game board). Talk with the rebel leader - you'll learn that aside from eating chips, they don't do much. Use the opportunity to suggest your own ideas.
Approach the projector and use the slides you have in your inventory. While commenting on them, choose the following options (which the lisping Janosch will be able to repeat without Rufus laughing at him) "A symbol", "An Organon bombing fort", "Our enemy will try to eradicate Deponia", "Our team will dare to attack", "I obtained topographical data locating one particular organon fort", "(...) detonate a bomb here and put an end to all life, marine and on land", "Goal and her brain implant might mean an important trump in our hand". The plan will be accepted, sparking a lot of enthusiasm in the progress. Baby Goal will agree to go to Doc's with Rufus. All that is left to do is to convince Spunky Goal.