In This Side of Brightness we are introduced to the character of Walker, living in the early 1900’s. Hired as a sandhog to help build the train tunnel that now connects Manhattan to Brooklyn, his life takes a series of turns after accepting the job. Deep in the tunnel’s underworld, Walker experiences something so profound that there is an immediate luminance and transcendence that outdoes the darkness he is surrounded by. McCann then parallels Walker’s story with that of Treefrog, a contemporary homeless man that survives by navigating his way through New York’s forgotten tunnels. In seamless prose switching between the two characters, McCann tells a story that challenges our notion of time and friendship, so that we come to realize how one person can ultimately embody all the stories that came before.