Does Din have to use different scents for his vials for this investigation? Because he remembers everything and I remember displacement(?) was mentioned in the previous book at some point. Which if I’m remembering correctly was old memories coming because of an association.

So surely he can’t use mint or the other scents he used in the last book or all that information would also be remembered? I hope the author explores this and now this is going to bother me while I read this.