Jen wakes up to find herself on a boat with six other people, with no idea of how she got there. She quickly learns that she and the others on board are dead, and that wherever they are is not the world of the living. She also learns what the others had before her; that somewhere along the river their boat is travelling on, there may be a way for them to get back, to cheat death and regain the lives they had lost.
Unfortunately their trip down the river is anything but easy.
Along the way they defend themselves against strange, mutated creatures intent on forcing them to pass on, stumble through their own missing - and unexpectedly found - memories, and grapple with the looming question of what befalls them should they fail, all while following the one rule they know they must adhere to to stay 'alive': stay away from the water.