I didn’t need a calendar to tell me that August had ended, and September was here—already—when I took a routine brisk walk recently early one morning. A slight breeze carried just enough humidity to remind me it was still summer, with air that was cooler, driven from pockets in the woods, tapping my shoulders. I thought of what marked this past month: school buses, the disappearance of bike-riding kids, spent heads of bee balm and coneflower. And I couldn’t help but to feel that there was something in the air.

We can easily notice a shift from one season to the next. From winter to spring, it’s the sun’s angle, warming temperatures, daffodils and crocus that pop their heads through defrosted ground announcing a new season. Spring quickly blends into summer and too soon fall seems to slide in through a back door where I know something is knocking, but I haven’t quite greeted it yet. I know fall has left us for winter when the temperatures drop to freezing and a landscape of harvest gold and burnt orange fades to a monochromatic dull gray.

This is the one time during the cycling of four seasons when I notice a shift that a calendar, a flower bed, or kid traffic doesn’t signal.

The difference I feel is not tangible. It’s more like reading between the lines of a book you haven’t quite figured out. You know the narrative is telling you something and you try your best to understand.

My early morning walks, or if feeling especially exhuberant, a run, take me to Glenview Woods near my home where I continue north to Blue Star Memorial Woods. I don’t know why I’ve consistently headed in this direction. Perhaps it’s the feeling of awe and curiosity when reconnecting to a familiar route, or knowing that no two experiences by bike or by foot will be the same. No, I won’t have the exact encounter with a pair of young male deer with fuzzy antlers or see that one blue heron gliding low along a branch of the Chicago River with a long slender branch wedged in its beak. But what I will have is an anticipation of the unknown, tucked into the depths of a darkened forest made by thick canopies of the swamp oaks. I’m in suspense as if awaiting to peak behind the rising of a drawn curtain. And there’s the new scents of spice from fresh cut wood, or the sweetness of the prairie of Black-eyed-Susan and Queen Anne’s lace that float a memory or create a new one.

Florence Williams in her book, The Nature Fix: Why Natures Makes Us Happier, Healthier, and More Creative, acquaints us with the term biophilia effect—an innate emotional attraction we have for other living things. Decades of research on the effect of biophilia show how strongly and positively we respond to open landscapes. One biophilia hypothesis says that we have a genetic disposition to be attracted to nature.

Such is the power of the natural world and of its seasonal changes, a book of open pages that keeps you turning them, wanting more. Your engagement might yield something that is perplexing, a thing that doesn’t quite fit along the horizon—a matted oval in the middle of a field of tall wild grass or a lone shoot of red leaves snaking around the tender greens of a sapling, or a misplaced turtle that has found itself in the sun straddling grass and the asphalt of a bike path.

Perhaps it’s Her way, for Mother Nature’s offer of the cycle of seasons, a rhythm to the expected, of birds’ migration, new fawns, cattails, and always a pair of cooing mourning doves, to keep us curious, thinking, engaged.

Perhaps it is the biophilia effect of attraction and connection.

It’s what cuts to the soul.

It’s the something that’s in the air.