On 20 August 1966, a boy flying a kite on Morro do Vintém, a hill overlooking Niterói, Brazil, spotted something that led him to two bodies. When police and firefighters finally reached the site the next day, difficult terrain having slowed their approach, they found two men dressed in formal suits, lying with hand-cut lead masks over their eyes, shaped like sunglasses but made entirely of thin sheets of metal. Nearly six decades later, no one has ever determined how they died.
Two Technicians, One Unexplained Trip
The men were Manoel Pereira da Cruz and Miguel José Viana, both electronics technicians from Campos dos Goytacazes. On 17 August, they left home, telling others they were traveling to buy work materials, and arrived in Niterói by bus at 2:30 that afternoon. Once there, they bought raincoats and bottled water, purchases that would later be found unopened alongside their bodies. A waitress at a local bar, one of the last people to see them alive, described Miguel as visibly nervous, repeatedly checking his watch as though working against a deadline only he knew about.
What Was Found With Them
Alongside the two lead masks, police recovered waterproof coats, two wet towels wrapped in a packet, an empty water bottle, and, most strikingly, a small notebook containing handwritten, time-stamped instructions. One line, translated, reads: at 18:30, take capsules, after the effect protects the metals, wait for the signal, mask. The notebook read less like a note and more like a set of directions the men intended to follow precisely, for a purpose that was never recovered along with them. They still had a substantial sum of money on them, roughly 3 million cruzeiros, which ruled out robbery as a motive from the outset.
An Investigation Undone by Time
The case was compromised before it really began. By the time authorities located the bodies and could arrange an autopsy, the remains had decomposed too badly for meaningful toxicology testing, and no cause of death was ever established. Investigators traced the men’s movements methodically, from their departure, to their bus arrival, to their purchases, to a reported (but unconfirmed) account that they’d hitched a ride up the hill in a jeep driven by two unidentified men, but the trail ended there. There were no signs of a struggle, no trauma consistent with violence, nothing to point definitively toward foul play.
The Theories That Filled the Gap
With no medical cause of death and an unexplained set of props, ranging from lead masks that would have blocked out light entirely, to detailed instructions about protecting “metals” and awaiting a “signal,” theories multiplied quickly. A friend of the victims, Élcio Gomes, told investigators the two men had been involved in spiritualist practices, and materials later found in their homes reportedly supported that connection. British ufologist Charles Bowen, who investigated related cases, connected this death to a similar 1966 incident, feeding a persistent theory that the men believed they were preparing to observe or communicate with something otherworldly, whether through occult ritual or, in a stranger reading, an attempted UFO encounter. None of this has ever been substantiated. A separate theory proposing accidental drug overdose was floated based on the “capsules” mentioned in the notebook, but with no toxicology results available, it was never confirmed either. It’s a similar unresolved territory to the Isdal Woman case in Norway, another death where physical evidence raised more questions than it answered.
Still Unresolved
Even the basic timeline carries an unexplained discrepancy: some records list the discovery date as 20 August, others as 6 August, a gap that was never definitively reconciled in the historical record. What’s certain is only what investigators could physically document: two men, methodically prepared for something specific, found dead on a hillside with no trauma, no toxicology, and no answer. Whatever the notebook’s instructions were actually for, the men who wrote them took the explanation with them.