At the top of the stairs is a door, already floating open on its hinges in the breeze. A placard above the frame repeats the welcoming phrase I recognize from the beach signpost: Surrender your sins. This demand, edging on low-key threat, grows poisonously sweeter every time I see it. Surrender your sins—what we’re all here to do. The inside of the treehouse office is a rustic, vacant space except for a whiteboard bolted to the far wall and a dozen half-moon school desks. Briggs weaves between the desks on his way to a chair with a stuffed red folder lying on top. “Take one of the closer seats,” he orders.

Before I can oblige, my heart stops at a magnificent view. Natural light cascades through a window, open-aired but shielded with a net of iron bars. The air up here is sweet: honeysuckle and mist, wet wood, river rocks; a soothing, summer smell. The trees are even different at this height. Below, the bases are wide and sturdy; here at the top, thin branches curl their crooked fingers toward the sky, which hangs like mounds of dark clay over Lake Monteverde. From this vantage, the edge of the island finally comes into view with a mossy-green clifftop and a waterfall dropping onto the rim of the lake. My awe lasts only another moment before the creature arrives: spindly legs creep over the windowsill, and a tarantula the size of my fist crawls inside.

I can’t even gasp; I leap backward (almost into Briggs’s arms, Satan help me), and my jaw hangs open as the many-legged spider rests on the ledge between two of the bars. Except it’s not a tarantula; its limbs are encased in a spiny shell. “It’s a coconut crab,” Briggs says, glancing up from his notes. “It’ll go away.” Almost at his command, the enormous crab scuttles across the window and out of sight.

“It’s a coconut crab.” Last week, the most exotic thing I’d ever seen was a white-tailed deer.

As soon as I catch my breath, I tap the bars barricading the window and ask, “These to stop me from jumping?”

“The bars have always been there,” Briggs says, arching his eyebrow. “Homosexuals are more likely to off themselves than their normal friends, and poofs with unaccepting families…well, they’re twice more likely than them, aren’t they? So, everyone here is at risk, and bars on my window make sense. Sit!”