After a Near Death Experience (an 'NDE') radically transforms the life of eccentric billionaire Nicholas Sheridan, he becomes obsessed with understanding the experience, recreating the conditions that opened the gate to the unknown. After recruiting others with similar experiences, they discover amazing connections, common visions and dramatic abilities among people who have come back from the dead. But what they haven't bargained for is that the gate opens both ways. Something has escaped from death and is hunting them. Something hungry...