London - Astrological glyphs for a sun/moon occultation have sprung up, crop circle-like, on Carlton House Terrace lawns ahead of Wednesday's Gemini solar eclipse.
The 11 degrees Gemini phenomenon occurs at the best possible angle to the the planet Saturn, baleful taskmaster and debunker of humbug.
News of the grass etchings saw betting plunge on the Queen's 11/8fav Derby contender Carlton House, named after the 19th century royal mansion which once occupied what is now the Terrace.
Worried bookies are probing reports that the zodiac signs straddling the grassy knoll from No 2 - which houses the Royal College of Pathologists - to No 5, the home of the Turf Club, are some sort of Grim Reaper warning.
"Sounds like an occult omen," Aintgottaprayer.con online bookies commented.
"It's either HM or her racing beast...wouldn't back either for a donkey derby, personally..."
Wednesday's solar eclipse at 11 degrees Gemini also occurs on the grim 10th anniversary of the Nepal royal family's massacre.
On that day Crown Prince Dipendra, the country's equivalent of the Prince of Wales, went on a rampage gunning down King Birendra, Queen Aishwarya and nine family members in a spat over his choice of royal bride.
He then topped himself with a shot to the temple after being told a UFO was waiting for him above Mount Kathmandu.
Fears that Wednesday's zodiac phenomenon means a right royal RIP were hastily dismissed in Newmarket, British flat racing's headquarters, where trainer Michael Stoute said "WTF?"
"Astrology's rubbish - and so's this rumor," stable hands were quick to point out.
"She's waited neigh on sixty years for a Derby winner and nothing, but nothing's going to bollox that ambition."
Kieren Fallon is 69.