It was a heavy metal miracle.

Acrassicauda had been through hell as a rock band in wartime Baghdad. Its practice space was bombed. Its members were branded Satan worshipers and received death threats for making Western-style music. Then they suffered through two purgatorial years as refugees in Syria and Turkey, killing time and dreaming of rocking out in the land of the free.

And on Sunday night, two days after the last of the band’s four members was resettled in the United States, they enjoyed what any metal fan would have to call heaven: bearhugs and “Wow, dude” heart-to-hearts backstage with Metallica at the Prudential Center in Newark. It probably wasn’t necessary for James Hetfield, Metallica’s lead singer, to surprise them after the show by handing over one of his guitars, a black ESP, and signing it “Welcome to America”; their minds were already blown.

“That’s for keeping the faith,” Mr. Hetfield said, adding as he disappeared with his entourage down a corridor, “Write some good riffs.”

Acrassicauda’s rock ’n’ roll faith was traced in a documentary, “Heavy Metal in Baghdad,” released in 2007. That film portrayed the members as ordinary if tenacious rock Joes amid the most extraordinary circumstances, and they continue to embody those roles in their new lives.