They gray sock should smell very familiar, at least, since Levi is right here. It might be a bit of a challenge yet, for Eren to sniff it out between time and the box acting as a barrier, but if that's the case, Levi will have to adjust the exercise to try again another time.

Luckily it seems like that won't be necessary. He watches Eren track around the area for a little while. Eventually, he closes his eyes and just listens to the sounds around him - Eren rustling about, the light breeze through the trees, birds calling. It's nice to just...detach for a bit.

He dozes for a few minutes, arms folded in front of his chest before waking to a now-familiar howl, and trudges off in that direction - it's the right one, so he can only assume Eren found what he was looking for.

"Found it, huh? Not bad." Levi picks up the box, dusting off the excess dirt, and opens it to show Eren he had the right one (which Eren probably realizes by smell, rather than color).

"Next one. Get going. I'm timing you now." There's a gold chain and pocket watch in his hand.