A ten issue miniseries split into two parts from Scott Snyder and Sean Murphy, published by Vertigo Comics, that weaves across billions of years of history.
Our main heroine is Dr. Lee Archer, a Cetological Vocalization Specialist (marine mammal songs), who has been professionally blacklisted prior to the story's start for exposing an environmentally toxic Navy sonar program. At the start of the story she is approached by the Department of Homeland Security to investigate a new, alien tune heard in the depths of a clandestine underwater oil drilling platform. In exchange for her cooperation, Archer's blacklisted status will be lifted, but that little interests Archer. It's the sound that alien tune that interests her. Because she's heard it before...
- Downer Ending: Part One concludes with the Mer sinking the mainland, and Dr. Archer in a small sub at the bottom of the sea, which has been damaged beyond repair by the survivors trying to stop what they thought was the only King Mer at the time. We then cut to Leeward, 200 years later in a mainland that's been flooded and destroyed, saying that her story starts here.
- Cliffhanger: "My name is Leeward, and this is where my story starts."
- Eye Scream: A caveman is bricked in for some unknown reason, the walls of his prison filled with drawings of the sea and the mermaids. Using some impossibly advanced piece of technology, he gauges out his own eyes.
- The book has a lot of these, since eyes (and tears) seem to be a recurring theme. The very first issues shows a man being rushed away to doctors after having something scarth his face so that his eye was just barely hanging in, before the monster is even unveiled.
- Hallucinations: Via a fast-acting toxin, the mermaids can make humans hallucinate anything from the ordinary to the impossible, and display some degree of being able to control those affected.
- Our Mermaids Are Different: The ones here branched off from a common ancestor, an "Aquatic Ape", millions of years ago. Where humanity left the shoreline and became land-based, they went deeper instead.
- Sirens Are Mermaids: It's suggested that humanity's unnamed sister species is the source of multiple seafaring legends, like that of the mermaids and sirens. This is justified by the ear-piercing screech they can emit.
- The Worm Guy: The comic opens with Dr. Archer studying whales at sea before Agent Cruz arrives to recruit her to study the captured merman.
200 years after the time of Lee Archer, Leeward is a young woman who tries to stay alive in the post-apocalyptic flooded wasteland that was once the United States of America. She's spent her life searching for a legendary signal left behind by those who lived in a time before the Mer flooded the world, but when she finally manages to get a lead on the mythical signal, she finds herself being pursued by a ruthless general, and a cold governess, members of what was once the United States government. The two seem determined, for unknown reasons, to stop Leeward from finding the signal, no matter what the cost...
- An Arm and a Leg: The Epilogue shows Leeward somehow lost a hand and replaced it with an advanced prosthetic.
- Ancient Astronauts: The final issue of the miniseries reveals that Humans came to earth on a giant spaceship, and drove the Mer, the native life form of Earth, to near extinction.
- Gainax Ending: Mermen are the native lifeform of the Earth. Humans came from extraterrestrials that were seeding planets, in order to terraform planets, and once mature, leave those planets and go plant more seeds somewhere else. Also, tears wipe memories away.
- High Concept: The first half is a horror comic. The 2nd is The Abyss meets Mission to Mars. Somehow, its supposed to make sense in the end as a whole.
- Precursors:What the Humans are. They just have forgotten about it.