"The Anomaly" by Michael Rutger

An audio book.

Nolan (43, his first-person PoV - his ex, Christie, is a successful writer) presents a YouTube program about Archeological mysteries. They're going to be on a Cable channel. Ken (producer), Molly (28), Pierre (cameraman, mid 20s), Feather (neo-hippy rep of sponsor), Jemma (cynic), and Nolan are trying to find a mystery cavern off the Grand Canyon. It was described in newspaper articles a century ago by Kincaid, later a Smithsonian. Dylan is their guide on a boat. While they're in private dialog with Nolan we sometimes learn about the characters' psychology - Molly had bulemia and fears tunnels.

They find a cavern that matches the description - man-made. Dylan stays behind while the others explore. They know they should turn back and let experts explore, but they advance further, curious. A rolling boulder cuts off the route back for all but Feather. She goes back for Dylan but he's gone. She returns within earshot, and they spend a night there. Next morning Feather has gone. Food and batteries are running out. A pool (their water supply) has gone cloudy. They find ancient wall art/writing. Molly tells Nolan about a childhood episode.

Feather says that she's killed Dylan. Her organisation wants to claim the discovery. Nolan says that Christie was unfaithful. He reacted by sleep with a friend of hers. Jemma, having drunk dirty water, chokes on her own vomit. A pterodactyl rips its way out of her abdomen. Ken kills it. There are other animals around. Ken distracts them while the others escape. The pool become a primordial soup with a sphere for each required element. Recalling Hopi legends, Nolan wonders if it's a sort of Ark programmed to create animals when triggered. They find a map of the world where their site and a few others are marked.

Dylan returns with a gun. He says that the site will start a new cycle of civilisation, humans being killed off. He's killed. A 9 foot humanoid with horns attacks. It's killed by Ken. They escape back to civilisation and meet Feather. Molly kills her.

5 days pass. Nolan meets a representative of the sponsors who has features resembling the humanoid. Nolan's told to forget what happened. Nolan and Chrisie look as if they're getting back together.

Other reviews

• Michael J McCann (As an opening 100 pages, [Part One] is really quite good. Rutger uses humor effectively to develop his characters, and his narrative at this point is clean and uncluttered, moving the reader steadily forward. Part Two, in which their experience takes a sudden turn for the worse, unfortunately fails to maintain the same high standard of storytelling. The action slows to a crawl ... When Part Three finally arrives, for those who are still tuned in, the answers to all our questions are revealed, and they turn out to be rather implausible but definitely strange and fantastic, in the old pulp magazine sense of the words.)