Chapter 18 was attempted today. It was a Fog of War mission, but was actually pretty simple. However, some other Pegasus Knight appeared, who I assume I need to get Florina my Pegasus Knight to talk to in order to get her on my “team”, but unfortunately I hadn’t chosen Florina as part of my group so couldn’t.
Was considering restarting the chapter, and then one of my characters died at the hands (or rather, sword) of Uhai, the “boss” of the chapter. Rubbish.