Gimme, Gimme, Gimme

In reality, the track is not so much lost as hard-to-find. It was a B-side on one of their later, less popular singles but has just been re-released on the band's
The song is famous amongst fans because it was due to feature on Abba's never-completed ninth studio album. It even has a rather grandly titled "fanclub", which is little more than a glorified webpage.
Beware: This is not the sort of Abba song you'll like if you're a fan of Mamma Mia and Dancing Queen. It bears more relation to late-period "The Visitors" Abba. You know, that cheesy sing-song synth nonsense that Erasure have been trying to emulate since 1992.