A married couple who have managed to remain blissfully happy into their autumn years, are surrounded over the course of the four seasons of one average year by friends, colleagues, and family who all seem to suffer some degree of unhappiness.

Poppy Cross is happy-go-lucky. At 30, she lives in Camden: cheeky, playful, frank while funny, and talkative to strangers. She's a conscientious and exuberant primary-school teacher, flatmates with Zoe, her long-time friend; she's close to one sister, and not so close to another. In this slice of life story, we watch her take driving lessons from Scott, a dour and tightly-wound instructor, take classes in flamenco dance from a fiery Spaniard, encounter a tramp in the night, and sort out a student's aggressive behavior with a social worker's help. Along the way, we wonder if her open attitude puts her at risk of misunderstanding or worse. What is the root of happiness?