Last crystal berry hint

[Vizer]

The hint is "where caravans get ambushed". I checked the Defiant Root caravan (the bug duo that sells you stuff, just outside of town from the west), and I combed the desert, but I couldn't find it.

[Saler]

It's on the screen where you fought the Burglar + Thief + Wasp Scout group in Chapter 3. I think it's somewhere south of the fork to Defiant Root and Lost Sands. You have to fly over a quicksand pit and go a bit further to reach it.

[Vizer]

Thanks, that was it! I had passed that spot, but I completely forgot to try flying over the quicksand.