Xeroch

The harvester then starts picking up gems and sockets, seemingly at random, looking closely at each one in turn, sometimes bringing a pair close together to see if there's any reaction. While he does so, his voice speaks inside the group's minds: If this scroll is to be believed, we have gained two good bits of information my friends. First: we are being observed, it's unsure to say even telepathy is uncompromised. Second: this observer thinks of us as light entertainment. I believe we can exploit this, if we play our cards right.

Finally, if he gets no further clue from the inspection of the objects, he speaks out loud and proposes pairing whichever gem is the smallest to the object with the smallest gem slot, and so on until the largest gem would be inside whichever object has the largest hollow.