Henry is trying to help Dorothy by removing the Desert Thorn that's stuck in her, but a crack now prevents access to her.
This is the low-spoiler guide for "A crack has opened up, in the ground." puzzle in Henry Mosse and the Wormhole Conspiracy. 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.