Leon and Luca are recalling parts from Chapter 2, which they seeming were unable to remember. Specifically, Leon is remembering his fateful bathroom visit (which resolved with Luca saving him), while Luca is pulling up her memory of when the group was escaping from the Spring Fair.

Interesting, Simon seems to have a means of restoring those memories. That’s… probably normal. Eh, better to not think about it! The important thing is that it’s all coming back to our heroes!