People in the train starts giving you looks, as you're talking to him with a sign language. They starts whispering and pity you.

Atallah notices this, once you both arrive at your destination, he takes you out from underground. You're clueless and kept talking to him with sign languages, until he stops your hand.

"What's wrong?" you asked him while kept doing sign language.

It was him all along, he's mute and deaf.