It is a pity the Door does not function more like a portal. I imagine people would be more amenable to helping you get the emotion you need if it was a matter of directing you to places where you could feed off of a larger population who would already be feeling the necessary emotions. There is a country on my world where slavery is legal. You would be well fed there.

[Despite Sorrow's explanation that it's not a portal, it seems to have similar enough effects to one that she suspects there might be avenues to explore.]

If the Null were no longer a threat, would you be willing to experiment more with the Door and look into sending us home?