Bob Daisley
The album was recorded by the line-up responsible for the previous year's "Abominog", but this time with a greater proportion of the songs written by the band members. Bob Daisley left the group shortly after the album's recording to rejoin Ozzy Osbourne; on the "Head First" tour former Heep bassist Trevor Bolder rejoined the band, effectively replacing his replacement, and remained with the band until his death in 2013.