"Nah," Sans says to Pluto, his skeleton wolf face doing little to get across his emotions. "That's this guy, here." He nods at Yuya, sounding a bit cheeky.

And then, to Yuya:

"Sorry, kid. The room where you smelled him last was the only evidence we have. They must have been moved somewhere else... with any luck, one those Architects will be able to tell us where."