In May 2004, Mustaine returned to his solo project. Contractual obligations to the band's European label, EMI, resulted in the recording's release as a Megadeth album. Mustaine reformed the band and contacted the fan-favorite "Rust in Peace" lineup to re-record backing tracks. While drummer Nick Menza agreed to return, both Marty Friedman and David Ellefson were unable to come to an agreement with Mustaine. Menza was sent home shortly after rehearsals began, a few days before the start of a tour supporting Megadeth's upcoming album. Mustaine said Menza was insufficiently prepared for the physical demands of a US tour, and "it just didn't work out". This was the first album without Ellefson. Chris Poland, who played lead guitar on Megadeth's first two albums, was hired to contribute guitar solos to the new album, working with Mustaine for the first time since the 1980s. Poland opted to serve only as a session musician, wanting to remain focused on his jazz fusion project OHM.