Granny Favors: Protagonists happen upon a nice old lady while she was “gardening”. She was actually doing something nefarious and needs to get rid of the protagonists in a way that doesn’t lead back to her. So she sends them on a series of increasingly tasks, hoping they’ll die by misadventure.
Originally mage-y these could be edited for other splats:
Jennassa's Worm: This strange parasite is named for the first victim. An Arrow mage by the name of Jennassa. She was an Obrimos and a sentinel of the Consilium of Zurich. She was sent on assignment to investigate an anomaly in Bern. There were reports of people acting strangely and seeing strange creatures when they went into the Aare. There she found a strange create that had floated down the Aare. She found in the crate a bunch of robin's egg sized green rocks. She took them back to the Arrow's headquarters in Bern to try and run some tests on them. While she was experimenting one of them hatched into a medium-sized snake like creature. The creature then bite her and crawled inside of her body. From there it drove her paranoid and insane. She eventually killed herself, but not before killing a sleepwalker that was assisting her. The entire compound was sanitized by the Guardians after an outbreak of the worms caused three more deaths. You can't find anymore recorded incidents of Jennassa's Worms.
Black Motes: You also find a report of an incident where some spirits called the "black motes" were encountered. These motes had the ability to attach themselves to the Amygdala of a person, and force them into a constant state of panic and fear. Once attached to the victims the only way to cure it was said to be death. However, a Master of Mind found that she could alleviate the fear response. The motes were eventually killed via subjecting them to bright lights, and the affects faded with their death.
Azkhahics: Abyssal creatures that live in the dark places. These creatures are said to have dominion over fear. With one touch they can cause someone to die of fear alone. Their powers range from causing hallucinations, mass paranoia, and lifelong mental scaring. They can be banished by facing them with by exemplifying everything they are not. Courage, healthy mind, light, etc.
The Lurking Terrors: Lastly. There is a creature referred to as 'The Lurking Terror'. You can't find if it is Abyssal or Spiritual, but it seems likely to be Abyssal. The creature seems bound to the laws of terror (whatever those are). It has the ability to spread fear like a disease and cause people to hallucinate.
The Laws of Terror: As previously mentioned. The laws of terror are a modern-day notion- according to the Libertines. And a primordial things according to the Mystagoguges. However, you come across a bit of research that is tangentially connected to them. About how the Abyss is spawning new monsters off of what Humanity is bringing into the world. And that the Laws of Terror are connected to several new creatures.
Fear As A Disease: As I mentioned previously. You come across notes and studies. A libertine has published a small essay on fear as a disease. Detailing his experience with a group of sleepers. How one of them gets afraid of something, tells about that fear, and then the fear spreads among them. Becoming stronger and harder to combat. something that could cure Durandal's child in Deus Solum.
Anguish's Tear: This is a legendary artifact said to be able to breathe life into even dust, so long as the dust once held the spark of a soul. It dates back to bcc. It was said to have been kept in an area of the world that is now somewhere part of Africa. It was said to have been formed from the anguished cries of a Life Archmaster whose child was killed by an abyssal intruder. Unfortunately this legend has never been confirmed, and the only images you can find of Anguish's Tears are sketches that are at least a hundred years old. The last mysterium expedition that went looking for it never returned. The one before that about two hundred years ago only one party member came back- a Mastigos master of space, who teleported back to his home base -and he came back wrong. He had signs of abyssal taint and was raving about living shadows.
Dunvegan's Jewel: This legend appears starting about six hundred years ago. Rumors are that deep in the bowels of Castle Dunvegan in Scotland there is a necklace made of perfected gold and perfected diamonds, that while it is worn the wearer cannot die and is afflicted by no disease. You do manage to find what is supposedly a photograph of it, but it is blurry and the glare obnoxious. The quality is so poor you're not certain you would even be able to properly describe it for sympathetic connections.
Janessa's Herb: The last lead you find is an herb created by life/matter Archmage that is said to cure any disease, even those that cannot normally be cured by life magic. The herb only grows in the ruins of her workshop, deep underground in the antarctic. There is a map of the antarctic listed and a couple of places where the mysterium /thinks/ her lab is... but they are not certain. No one has ever gone and come back from Janessa's lab. People tend to disappear when they go to the suspected areas in the antarctic.