Small hint :
Qb abg jbeel nobhg gur frnfbaf lrg. Gnxr n pybfre ybbx ng lbhe vgrzf, bar zvtug or fbyinoyr.
Huge hint :Znlor gurer'f fbzrguvat nobhg gur cvyy'f ebgngvat urnq gung pbhyq or yvaxrq gb fbzrguvat ryfr ?
Aaah--the huge hint was a huge help, thank you! ^_^
(The small hint didn't work because I had largely discarded the interaction in question due to there being no apparent effect to or feedback from it, I think.)
Okay, hopefully I'll be able to progress now! ^_^