The CIA burst onto Twitter last year in a ball of quirky glory, poking fun at its secretive reputation with its very first tweet: “We can neither confirm nor deny that this is our first tweet.”

Since then the agency has shared a lot of its history and heritage. But the wackiness hasn’t stopped completely: It posted a cat photo last month to celebrate its first anniversary on Twitter:

Still, things spiraled into weirdness in a whole new way Thursday night. The agency posted a series of messages to coincide with Shark Week, Discovery Channel’s long-running annual homage to the toothy ocean predator. It started this way:

Yes, that’s Julia Child, the famous chef who died in 2004. And there’s a real tie: During World War II, she served in the Office of Strategic Services, a predecessor of the CIA. Her real name was Julia McWilliams.

“This was years before she became the culinary icon of French cuisine that she is known for today,” the CIA said in a news release posted with the tweet. “In fact, at this time, Julia was self-admittedly a disaster in the kitchen. Perhaps all the more fitting that she soon found herself helping to develop a recipe that even a shark would refuse to eat.”

The recipe was sought beginning in 1942 because at least 20 U.S. naval officers had been attacked by sharks during World War II, according to the CIA. The OSS eventually settled on a recipe with copper acetate as the main ingredient.

“To create the repellent, copper acetate was mixed with black dye, which was then formed into a little disk-shaped ‘cake’ that smelled like a dead shark when released into the water,” according to the CIA. “These cakes could be stored in small 3-inch boxes with metal screens that allowed the repellent to be spread either manually or automatically when submerged in water. The box could be attached to a life jacket or belt, or strapped to a person’s leg or arm, and was said to keep sharks away for 6 to 7 hours.”

The CIA continued with a series of tweets laying out that story, and then noted this interesting training manual issued by the Navy to dispel shark myths:

The guide included some seemingly obvious advice. You know, like: “Don’t let the shark mistake you for a corpse.”

The CIA shared the Julia Child animated GIF and repellent story again a few hours later, and then offered up this gem at the end of the day after Shark Week’s Twitter account questioned whether the story should be classified:

Again: Don’t dangle your feet out of a boat for fear of having your foot bitten. Also, never believe a shark story.

Unless it involves Julia Child, that is.