Each morning, most London Underground commuters from Hampton Court to Waterloo Station observe a few unspoken rules: don’t eat smelly foods, avoid loud cellphone conversations, and, most importantly, ignore your fellow passengers, even the ones you see every day. Iona Iverson, whose colorful life has broken the mold in most ways, generally follows these rules. But when a commuting business man chokes on a grape in front of her one day, it breaks the ice between Iona and a small group of her fellow passengers – Sanjay, a lovelorn nurse; Emmie, a sweet graphic designer; Martha, a struggling teenager; and Piers, a workaholic father (who survives the grape encounter). In the weeks that follow, their unlikely friendship transforms each of their lives.