Ah thank you for the reply, but for me, he gave me a bug's net when I gave him a rune 😅
Since this comment was ~4 months ago, I'm assuming you already got it or dropped the search. But just in case, the second rune is found during the sign puzzle right before the lamp post puzzle. The hint is to turn both signs that say "Secret" so that it follows a direction, one opens a path for a coin and another for a rune.