You'll start at a campsite in a previously inaccessible section of Macalania Woods. Talk with your party members, save and head down. You can't go right, and if you go left Bevelle guards will chase you away. So head down and follow the path along, past Kimahri who won't say anything to you. You'll get to watch a really long sequence complete with music video cinematic of Tidus and Yuna kissing. Afterwards, try to leave and Yuna will come with you back to the campsite. When you regain control, run back into the area you were in and check the left-hand side for a chest containing a Lucid Ring. Back at the crossroads you can go left and then left again to re-enter the main part of Macalania Woods, but otherwise follow where your party went to the right. You're at the entrance to the Calm Lands now. Take a look at the map, save, then head on up the slope, following the red arrow.