On a bitter winter's day in 1916, deep below the streets of New York, a group of men is working in one of the huge pressurized tunnels that will make up the subway system. Suddenly, a tiny hole appears in the roof of the tunnel and the air rushes in, sucking the men up through the bed of the Hudson, to be suspended on a spume of water high above the river. Almost 90 years later, Treefrog, a homeless man, stumbles through the same corridor, under the twirling flakes of snow, to his makeshift home under the city.A love story in three generations, this is also about hope and despair and survival.