This amusing film gives Ringo Starr and Leo McKern opportunities to shine alongside the Beatles. Ringo finds himself with a magical ring he can't remove, which turns out to be problematic because Leo McKern’s character, "Clang," intends to douse the ring-wearer in paint and then offer them as a sacrifice to his peculiar deity. Once Ringo grasps the danger he's in, he seeks assistance from some scientists, but that only escalates things. It turns out those scientists are also interested in the ring because of its unusual properties! If it can’t be taken off normally, "Foot" (Victor Spinetti) and his clumsy companion, “Algernon” (Roy Kinnear, always dependable), will need to try more extreme methods. What follows is a mix of humor reminiscent of "Fu Manchu," "The Pink Panther," and "Dad's Army," complete with chaotic physical comedy interspersed with Beatles songs like “Help,” “Ticket to Ride,” and “You’ve Got to Hide Your Love Away” – all connected by snippets of Beethoven and even Wagner. It is a straightforward comedy, very much reflecting the era in which it was made, and Richard Lester lets the band members be quite entertaining while their more experienced acting colleagues handle what serious scenes are required. The story apparently owes its existence to the creator of the sewing machine, although her name wasn't actually "Singer"!

Source on TMDB