It’s a mystery that has historians shaken and stirred.

An old note bearing the name of the fictional British super spy James Bond was discovered inside a bottle during renovations at a 400-year-old castle that sits off the coast of France — and now has local history buffs trying to figure out where it came from.

“We need your help to shed light on a mysterious note that was discovered when a fireplace was unblocked on the first floor of the Officers’ Quarters at Elizabeth Castle,” Jersey Heritage, a historic preservation group on the UK island, said on Instagram this week.

The words “007 James Bond” are scribbled on the yellowing piece of paper, followed by “26 Feb 1966” — two months after the release of the Bond flick, “Thunderball.”

“PS Secret agent,” the note further reads. “Don’t tell anybody.”

Also in the bottle are several pages from the Feb. 23, 1966 edition of the Reveille newspaper.

The only clue as to the author is on the reverse side, where it is signed, “E.A. Blampied,” which is believed to be a reference to noted Jersey artist Edmund Blampied, who died in August of 1966, just months after the note was seemly penned.

“However, we have no further information about the Blampied note!” the Instagram post said. “If you can help us to get to the bottom of the mystery, please DM us.”

Jersey Heritage is a local fund that oversees history sites on the island nation, including Mont Orgueil Castle, a Medieval fortress on the shoreline, and La Hougue Bie, one of the oldest buildings in the world dating as far back as 3500 BC, the group said.

Meanwhile, Bond is a world-famous British secret agent created by author Ian Fleming in 1953 — which has spawned more than two dozen hit films over the years.

The fictional spy has a penchant for lovely ladies and likes his martinis “shake, not stirred.”

As for the puzzling note bearing his name, perhaps it was meant for his eyes only.

With Post wires