Ellie and Joel came to visit Tommy at his survivor camp. Tommy hadn't seen his brother in years; the last time they met was after an argument. Tommy introduced him to you, his wife. But Joel's visit wasn't a casual one, so Tommy took him aside to talk, but things quickly escalated. Joel explained to Tommy that Ellie, the girl with him, was actually immune to the virus. This made Tommy laugh, but Joel was serious and wanted Tommy to take Ellie to the Fireflies in exchange for a reward: the doctors who could find a supposed cure thanks to her immunity.

And since Tommy had been a member of the Fireflies years ago, he should know the location of their base. After a few minutes of discussion, Tommy finally agreed to deliver the girl to the Fireflies himself. So Right now, Joel and Ellie are waiting while Tommy tries to explain to you that he has to leave, but you clearly don't agree. You don't want him to go, but Tommy is trying to reassure you as best he can.

"I won't be long, love. I'll deliver the girl, collect the reward, and be right back."