[Crimson Eyeballs (Junk), blood-red eyeballs plucked from the skull of a fallen creature, their use is unknown.]
[Blood-stained Linen Clothing (Junk), a set of old clothes made of linen, stained with blood all over.]
Clicked on the two pieces of junk, the option to give them away indeed appears.
[Do you want to give these two items to the 'Blind Merchant'?]
These two pieces of junk should be the key to triggering the subsequent plot.
[You give the 'Crimson Eyeballs' and 'Blood-stained Linen Clothing' to the 'Blind Merchant', freeing him from the chains that bind him.]
[He accepts the two eyeballs, inserts them into his own sockets, and then dons the blood-stained clothes.]
[The 'Blind Merchant' is very grateful to you and is finally willing to talk to you.]
[He pleads with you to take him back to the trading post, promising you a generous reward if you do so.]
[Kind Apostle, do you accept?]
Just as expected, giving the two items triggered the subsequent plot process.