
Selena Murphy is commuting home on the train from NYC when a beautiful stranger in the next seat strikes up a conversation. The woman introduces herself as Martha and confesses that she’s been stuck in an affair with her boss. Selena, in turn, confesses that she suspects her husband is sleeping with the nanny. When the train arrives at Selena’s station, the two women part ways, presumably never to meet again. Then strange texts from Martha arrive and the nanny disappears.