What is it about unsolved mysteries that captures our curiosity so completely? I can’t say, but given all of the television shows, movies, articles, and other media with huge ratings success that delves into these cases (Making a Murderer, anyone?), there’s no denying there’s something there.

Below are 4 that are especially creepy, and it’s not helping matters that no one seems to have the slightest clue how to solve them. Or even where to start.

4. The Lead Masks Case

In 1966, a Brazilian boy who was innocently (so he claims) flying a kite stumbled upon the bodies of two engineers on the side of a hill. It was impossible to tell by looking at them what happened (and I assume the cops dismissed the boy as a suspect). They were dressed immaculately and – very strangely – wore lead masks designed for protection against radiation.

Photo Credit: Reddit

The case got stranger as the police dug up details about the men, who were electronic technicians, and what they did before climbing that hill. They bought raincoats and then went into a bar to buy a bottle of water (which was found at the scene). In the bar, one of them was reportedly very nervous.

That’s it.

Oh, except for a notebook that was also found with the bodies, and here’s where things get really weird. It contained a note that translates to:

“16:30 be at the agreed place. 18:30 swallow capsules, after effect protect metals wait for the mask sign”

Not much of that makes sense, but if they took capsules, perhaps it added up to nothing more than a planned double suicide, right?

Maybe. Maybe not.

For one, the scribbled note talks about what they’re planning to do after they take the capsules, right? And not only that, but they had a coupon to return the water bottle later that day. Sadly, a lack of preservation rendered toxicology reports unavailable, which means we’re left with far more questions than answers.

Why were they taking capsules in the first place? What was the radiation gear for? Did they think something was going to happen? What metals needed to be protected? Perhaps most curious of all…what killed them?

It’s a mystery that seems determined to go down in the history books unsolved.

3. The BC Feet Mystery

Yeah, you read that right.

Over the course of the last few years, EIGHT disembodied feet have washed up on the shores of British Columbia. The severed feet have all been attached to running shoes which, according to experts in these sorts of macabre things, makes sense. Our ankle joints are relatively weak, so a body thrown in the water would naturally, um, break apart there. Add a pair of floaty soles, and there you go.

Photo Credit: The Spec

Only two of the feet are a matching pair, and they belong to a man who police claim was a suicide risk. But all four (or more?) victims can’t have killed themselves in the water while wearing tennis shoes…right?

I mean, I guess it’s possible, but it doesn’t seem very likely.

There are other theories as well. One is that the people were all involved in a boat or plane accident, but the fact that they were found carried by different currents seems to render that one unlikely, too. Most people seem to think it’s the work of a serial killer (and I do, too), but as of now, there are no suspects.