When I try to ink rough karstic rock formations, they turn smooth and rounded (like Mochi’s   ).

Karst happens when rock is dissolved by water, and if the rock is soft (e.g. limestone), the result – from the human perspective – may be impressive cave systems or dangerous ravines and sinkholes. Karst is named after a region between today’s northeastern Italy and Slovenia, the Karst plateau.

Falco is referring to the Sermon of the Mount again (Matthew 7:14, Douay–Rheims 1899 American edition, natch). To quote the Phrase Finder: “[…] the most common question about this phrase concerns the spelling – should it be ‘strait and narrow’ or ‘straight and narrow’? Well, that depends on just how pedantic you want to be.”

Rereading the Sermon of the Mount, it strikes me how often it comes to my mind when I’m writing this story. There is something for every character in it.