After you have chased the boy and he tells you how to go to the docks, go there. Collect the marbles then wall forward to the beam. Jump on the beam and go to the end. You must go to the end of the beam. Do not jump when the action light first appears, but instead go all the way to the end of the beam or you will fall into the water. After you have jumped on the train, use your insight to see where to jump next. Use your Sloth form. When you land on the box, turn back to the left and jump to the next sloth swing, which will take you to the next level up. Collect all the items. Use your Insight on the two birds before you get too close and they fly away. Use Sloth or Bird form to jump down to the pillar. If you use the Bird form you can control where you land easier. When you get to the second pillar you can either collect the items to the left bu jumping from crate to crate or by just climbing up from the second pillar and then changing to Sloth form. Use Insight to see where to jump next. When you leave the sloth swing, you will land on a beam and go to a second beam halfway across the last one. Exit from the second beam to the train. Go to the end of the train by the crane.