You enter a lab of some sorts as a shortcut to get to the CORE because the other entrance is blocked off and Alphys suggested it. You got in with the help of Alphys and come across two skeletons 1-S and 2-P. They notice you and start to say, in a different language you somehow understand

S: Ah heck I though he already finished the tests today but there isnt usually another person taking us to them?

P: oh they could just be an assistant and hopefully there’s not gonna be any more tests today!