Brinsley Street is your normal bustling city thoroughfare with four-story houses abutting the sidewalk. But their rather unremarkable exteriors hide surprisingly rural gardens--and family dramas.

In number twenty-three live the Coopers. Married for six years, Kate is a stay-at-home mother of two young sons. Her husband travels frequently for work, leaving Kate alone to care for the kids, the house, and herself . . . if there's time. Their marriage hasn't quite turned out the way she thought it would; Kate and her husband seem to live in different worlds, moving further and further apart. It's no wonder that she sometimes relishes his absence . . .

Next door are the Greens. Samuel has left the corporate world to work on his novel. His very competent wife, a psychiatrist, is the sole breadwinner. Their union works like a well-oiled machine, including their relationship with their sixteen-year-old daughter, who struggles to find ways to rebel against such perfectly understanding parents.

But in the midst of a blistering hot summer, the neighbors, who share a wall, will find their lives entwined. Seeing and hearing Kate throughout the day, Samuel becomes obsessed with her. Kate, lonely and feeling unappreciated, finds herself unmoored, ultimately discovering that danger doesn't come from outside their safe and comfortable world, but from within . . .