Dr. Marcus, a renowned psychiatrist, has selected 6 severe mentally ill and dangerous patients from the Spring Valley Mental Hospital to interview as part of research for his new book. As Dr. Marcus interviews each patient, one by one the horrors they have committed begin to unfold. However, Dr. Marcus soon learns that there is one patient who ties them all together - Patient Seven.
Based on an astonishing true incident that took place on the frigid seas off Iceland in 1984, The Deep fashions a modern-day everyman myth about the sole survivor of a shipwreck, whose superhuman will to survive made him both an inexplicable scientific phenomenon and a genuine national hero.
Oli, his young girlfriend, and a scheming colleague are fleeing the Icelandic financial crises with a fortune in forbidden cash stuffed into a duffel bag. They head for Spain in their boat under cover of night. The seas rage and a horrible accident occurs. Marooned on a freezing outcrop of rock, the tension builds as the three violently disagree as they take drastic measures to survive.