“That first winter we were together, your father built an iceboat,” she told him. “When we put on our skates and took that thing out on the pond, it was like we were flying. He was more fun than anyone I’d ever met.”

“How did things get so messed up?”

“The world gets in the way, honey,” she told him. “You’re trying to support a family, you’ve got all these responsibilities ... it just gets so much more complicated. There isn’t a whole lot of time left for stargazing anymore.”

“Other people’s parents have responsibilities too,” Nate said. “They don’t shoot themselves.” He drew in his breath and waited, not sure what his mom would do, but she just sat there like she was thinking hard about what to say next.

“Some people are just sturdier than others. Like your grandpa. Whatever happened to him—even if a fire wiped out this whole place and everyone in it—I can’t picture that man caving in. He’s one of those people who march on, no matter what. Someone like your dad doesn’t have as firm a grip on things. He takes things so hard.”

“We should have done more to make him feel better,” Nate said softly. “We should have helped him.”

“It’s one thing to rescue a person when they’re in the middle of a lake and they can’t swim,” she said. “But rescuing someone from what’s going on in their own head, that’s a lot harder.”

Another time, he would have said something to her about how unfair it had been for her and all the other adults to leave him and his sister in the dark the way they had. But he knew his mom was doing what she thought was right, so he decided to leave it alone for once. He figured he and his sister would get to Butte without her help, and that was probably the best way to do it.

He was grateful for this little moment that had passed between the two of them—the fleeting experience of hearing what she really felt. Like a flashing ray, shooting through the swirling atmosphere of a cloud chamber, lighting up for a second, and then leaving you in darkness again. Only at least now you knew: Just because something was invisible most of the time didn’t mean it wasn’t there.

Twenty-Seven

FRIDAY NIGHT BEFORE THE SCIENCE FAIR JUNIE CAME into Nate’s room. He had heard her singing along with “Mrs. Brown, You’ve Got a Lovely Daughter,” and he figured she’d fallen asleep when the singing stopped. But she was wide awake.

“I’m worried about something,” she said. “What if there’s still no star particles at your school? What if we beam the light in the cloud chamber and all we see is the swirling gases?”