A Keerosin is an environmental tool used for automated bio-sustainability.

"As we peak in synthetic composition, there's little choice but to find a new Source Model. It's the old one the Constructors are using that got us here in the first place, right?

Thankfully, my brother and I just happen to have one of these."

He pulled the drapes off a Keerosin housing a plant. I hadn't seen one of those in centuries. And the plant? Millenia.

"So, is this proof enough for you to help us get to one of those Interfaces?"