What if you just walked by the love of your life, but didn't even know it? Tess is in Florence on vacation before starting university in London. Gus is on holiday with his parents after a tragedy shattered their lives seven months ago, and is planning for medical school in London. Chance brings these eighteen-year-olds together for a brief moment-- and then sets them apart. But it's only the first of many times their paths will crisscross as time passes. Over the next sixteen years, as their lives diverge from those they'd envisioned, the possibility of Tess and Gus connecting once more seems slight.