[Sad to break it to you later, Sebastian, but those tiepin and cufflinks are definitely red herrings.
Ciel's quiet for a few moments, taking in their surroundings (plebeian but acceptable) and watching for any other stray monsters (clearly all scared away by Sebastian's earlier display of "crunch! goes the unicorn~"). He's still looking at the lake they're passing when he finally breaks the silence.]
Lizzie will be worried if we don't return soon. And my mansion will be ruined without you there to keep an eye on the others. [Also to be translated as "Sebastian, I'm extremely worried about leaving ourmy loved ones on their own to fend for themselves, and I'm worried that by the time we return, they'll have all blown themselves up to kingdom come, whatever shall we do?"]