Newt ushers Thomas out of the meeting so that the other Keepers can discuss what they want to do without him interjecting.
Thomas explains that he has his own reasons for volunteering to be the one who sacrifices themselves to the Grievers. He has guilt from his involvement in the creation of the Maze, and he secretly holds out hope that he can fight them off long enough for someone else to enter in the code. Our hero.
Newt tries to assuage his guilt (Thomas is, after all, only a sixteen-year-old kid), and then says that he's going to convince the rest of the boys to follow his plan as long as they all go together. No sacrifices.
Thomas agrees, and they both decide the best time to plan the attack would be at night, when hopefully a lot of the Grievers might be running around the Maze. Oh—and they should do it tonight before another kid dies.
Thomas goes to sit by the Box to think for a while, and fills Teresa in on the plan via telepathy.
She meets him there, and Thomas admits that he's really scared.