Day 666

They fished it out of the bog when they were draining it to make way for new housing. It looked like a fresh corpse so it was taken into the city morgue for autopsy. Apart from being caked in mud and bog slime, it appeared to be a perfectly normal human body.

As they washed it clean, where untold years of mud slid away, where flesh should be there was nothing. They could feel the body there but without the mud they couldn't see anything. Whoever they were, they were somehow invisible.

Their blood tests showed they weren't human at all but some combination of ape and squid. A creature engineered to be like us but utterly unseen. Stranger still when they tried to gauge the time of death the results were that the body was hours old but the bone marrow samples showed it to be somewhere between five and six hundred years old.

It was kept locked up tight in a separate area of the morgue until proper transport could be arranged to ferry it to a laboratory fur further study. The samples that they'd sent only made the forensic team there hungry for more data. Guards at the door made sure that only authorised staff entered during opening hours and nobody else.

After the body was transported some three days later it was found that every other body kept there had gone as well. All that was left behind was the faint odour of decay and a puddle of something akin to saliva but much thicker. The DNA from these remains matched the humanoid corpse.

Upon looking back at the CCTV footage from the morgue at certain times during the night, when the security staff were distracted, the small vents along the bottom of the walls could be seen slowly opening and closing.