Best way to combine fantasy, science fiction, and horror in one contemporary setting

What do you think would be a good way to combine these three speculative fiction genres into one whole setting set in modern times without it being a superhero universe?

What I would do is just make it something like the World/Chronicles of Darkness tabletop RPG setting, and add all kinds of sci-fi elements like lots of new advanced technology, like things such as all cars being electric, trans-Atlantic/Pacific tunnels, being able to clone extinct animals, cures for diseases that are currently considered incurable, robots that are able to help humanity, etc.

On top of that, there being advanced alien civilizations within the far reaches of space, as well as a Hollow Earth existing beneath the Earth's surface. To go even further, there would be various gods and deities (such as Cthulhlian deities), as well as ancient civilizations that were never known to have exist (like Atlantis) and parallel dimensions that are separate realms.

Any other ideas to use?

The easiest way would be to avoid having any one person or another amass any superhuman advantage.

I'd go with a B.P.R.D. or Atomic Robo-style team of scientists sent to investigate those kinds of matters. However, rather than inflating their technological arsenal and tacking on a bunch of excuses as to why it doesn't amount to much otherwise, I'd focus on gadgetry that simply counters the respective weird phenomenon, without having revolutionary applications otherwise. Kinda like how garlic and holy water can take out half the bestiary of any modern fantasy setting, but amount to condiments and disinfectants otherwise.

I'd also go with organic technology for any aliens come to visit. Sure it's cliched, but it at least it's more believable that human scientists wouldn't be too quick to analyse and reverse engineer it.

So, a bit like the TARDIS - living, cyborg technology and Magitek.

For the Cosmic Horror Story elements read John Dies At The End cause it does so in modern setting.

I think the problem is the contemporary setting. Sci-fi and horror have a long history of meshing well (the Alien Franchise being one of the most famous), not to mention going for full blown Cosmic Horror. Similarly fantasy, especially its darker elements can do horror as well and its not a stretch to mix that into an Urban Fantasy setting. But getting that to play nice with the sci-fi elements is trickier.

I can think of a few things that might help guide you. Only have a single masquerade. Having both alien and magical worlds be hidden from the human world and each other is making things harder than it needs to be. Also have the horror come from either the fantasy side or the sci-fi side. You can do both, but that's going to be pretty damn bleak.

I can think of a couple of ideas, but some of them are going to stretch the "contemporary setting" or at least inevitably date it.

• Option 1) Urban fantasy setting has to deal with a First Contact scenario
• Option 2) Alien spaceship/escape pod/whatever crash lands on Earth and finds out that humans aren't the only locals (this has a problem in that you have to explain why the alien isn't aware of magic but there are some outs such as making the aliens aware of magic but you're crash-landing alien be a Muggle-equivalent
• Option 3) If you want to ditch the alien aspect, have a Next Sunday A.D. and some sudden breakthrough in technology and how it impacts the Masquerade. Such as an Instant A.I.: Just Add Water! scenario threatening to expose your Friendly Neighbourhood Vampire (accidentally or deliberately).

The biggest concern is not empowering the protagonist that much, horror unlike other work in the oposite way, with chararter having in disavantage against....well, whatever the hell out there in the unknown, when you empower to much it become a action thing which ruins the feeling.

I sugest you mix fantasy and sci fi tropes like shadowrun or warhammer, that could work best.

If you want inspiration from something that combines fantasy, science fiction, and horror, look no further than the Shin Megami Tensei games.

I'd say the difference between sci-fi and fantasy is more or less arbitrary - Lovecraftian horror for instance features plenty of ancient aliens being worshipped as gods, devices akin to magical artifacts, etc. Getting them to mesh together might simply involve the different perspectives of various characters.

As for the matter of empowerment, classical horror stories like Dracula rely on a balance between the power of the monster, and the knowledge of the monster hunter. The things that go bump in the night are scary, but there is a method to their malice, a way they function in the world, a weakness to be exploited. The horror factor comes precisely from the race to find that weakness before the monster can find you. And it's a pretty fine balancing act - tip it to one end, and it becomes a Buffy episode where almost every vampire is cannon fodder; tip it to the other, and it's a Call of Cthulhu session, this being the only game where knowledge inherently makes characters weaker (unlike the actual source material). Once you have that balance however, you can still create action stories, like in The Mummy Trilogy, without it becoming a superhero setting.