It was two days later, a Monday afternoon, when we met again for band practice. Some kids had made fun of us at school, just as I had predicted, but not that many. Belman kept on with the Harry Potter wisecracks and the third-grader jokes when he came over to our table at lunch, but we tried to just ignore him. There was going to be another All-Ages Open Mic Night soon, and this time we planned to be totally ready.

We had just set up our instruments and were in the middle of tuning when all of us suddenly stopped.

“Did you hear something?” I asked.

Greg nodded. “It sounds like a trumpet,” he said.

“But where is it coming from?” I asked. “It was really far off, but now it almost sounds like it’s right here in the room.”

Julie smiled and pointed behind us. We turned around quickly and nearly fell over. It was William Foxwell!

“Hey there,” he said, holding the beat-up old trumpet. “Hope I didn’t scare you with my playing. I’ve sort of been practicing.”

We all jumped up and down and shouted and stuff while he just stood there grinning. He seemed to be all there this time — no flickering or fading in and out, no faraway voice. It was like the first time he showed up in my room so many weeks ago.

“I just came to thank you again,” William said when we finally quieted down. “Only this time for solving the mystery.”

It was our turn to grin. “You’re welcome,” Greg said. “But you didn’t need to thank us. We should be thanking you for everything you did in the war and all.”

William might have actually blushed — it was hard to tell since he was still a ghost — and then he said he just had one more favor to ask, but it wasn’t a big one.

“I was wondering if I could try to play a song with you guys,” he said. “Kind of a farewell song. Before I have to go.”

“Sure!” Greg said. “Anything! You name it.”

“Well,” William Foxwell said, holding up the trumpet again. “There was this song that was popular back when Betty and I were first going out. They used to play it on the radio. You might say it was sort of our song. Every time I ever heard it after that, I’d think about her, and she said the same thing — that it always made her think about me. So I was hoping we could play that one.”

But then his face fell. “But I guess you probably wouldn’t know it, now that I think about it. Heck, you probably never even heard it before.”

“That’s not a problem,” Julie said brightly. “Tell me the name of it and I’ll find it on my iPhone. We can download it from YouTube, and I can find the lyrics and arrangement for piano and the chords for guitar online, too.”

William Foxwell gave her a blank look. He obviously had no idea what she was talking about.

“Never mind,” Julie said quickly. “Give us a minute and we’ll figure it out. Just tell me the name of the song.”

William Foxwell smiled. “ ‘All This and Heaven Too.’ ”

We raced upstairs to get cell phone reception and Julie did all the things she’d told William Foxwell she would do so we could figure out how to play it. She even used Uncle Dex’s printer and printed everything out for us.

“What’s all this for?” Uncle Dex asked.

“No time to explain,” I said, hoping that would be sufficient.

Uncle Dex shrugged and turned his attention to another customer walking into the store. “Okay,” he said. “Catch you kids later.”

Julie led us through the arrangement a couple of times until we sort of got it. William Foxwell joined in on the trumpet, pretty rusty at the beginning, trying to play the melody, but after a while, he got it and kept going. We followed along on our instruments, grinning at one another, not quite believing this was happening — playing music with a ghost!

It was kind of a goofy old song, the kind nobody listened to anymore, not even my parents, or probably even my grandparents. But the more we played it, the sweeter it seemed to be. I mean, still corny and all that, but it made you feel good inside. I closed my eyes and I strummed my guitar, for once not having any problem remembering the chords to a song. I don’t know if Julie and Greg closed their eyes, too, but we all seemed to be in a sort of trance, playing on and on, with William Foxwell’s trumpet getting stronger, and clearer, and, yes, sweeter.

And then, I realized, the song was over, and William Foxwell was gone, the trumpet lay carefully on the floor next to that old trunk where I’d found his navy peacoat and the letter to Miss Betty Corbett.

Everybody was quiet for a moment as the last haunting strains of “All This and Heaven Too” echoed in our little basement practice room — none of us quite knowing what to think, but all of us happy that William Foxwell had found his peace at last.

And then Greg asked me, “Hey, what else do you think is in that old trunk?”