The Staircase in the Woods

Cryptids and folklore are always interesting themes in horror, and often manage to add a certain atmosphere to novels - this one was no exception. Years ago, 5 friends went on a camping trip and came across a staircase in the woods. But only 4 of them returned. They've all moved on, or tried to, and when they come back together for another camping trip in their late-20s / mid-30s, they encounter the same staircase again, only deciding that this time, all of them will go on the journey upstairs. They land in a sentient house filled with horrors, not knowing what is real, and with no way out... A thrilling novel, unsettling, creepy and leaving me on edge at times. The house gave me strong vibes of "The Haunting of Hill House"!