"The expanded earth" by Mikey Please

An audio book

On July 2nd - "The Descent" - people shrank to 10% of their height. Many people didn't survive the shrinking (pacemakers, artificial hips, cochlea implants, etc, didn't shrink). Millions of years ago, therapods suffered the same shrinkage. Elizabeth Godwin runs a research project in the New Forest about plankton being a superbeing - their dead and living bodies forming a binary code. She wants to conect with it, with God. A young researcher Lazlet wants to work with her. He creates a connectome so people can connect with a pool of plankton. Religious fanatics take over the project, taking Lazlet away.

There are various little, independent stories - "Elsewhere". All astronauts but one die. She returns to earch with a memorystick containing data about July 2nd. On an island, battling parties stop arguing because there's so much more land now. Some people see the collective plankton as a God correcting the faults of mankind.

Giles wakes, shrunken. He wants to find his daughters - Eva, who has a weak heart, and Sadie. Seeking a phone charger he finds a tent village of survivors. They build a car needing 6 to drive it. Cats and dogs are frightening. Alwyn is killed with a scalpel by a woman in red (actually it's paprika, to keep animals away). Children have set up their own tribes and try to kill the adults using fireworks, etc.

Matilda (a paramed) and Bob (Police) attend a traffic accident where people's clothes are left, and there's a shrunken body. They visit a nearly building. Shrunken Godwin is there. She thinks her experiment might have caused people to shrink in the range of a km or 2, and is worried that Lazlet will cause an event that will affect the world. She thinks that in a coma aren't affected so she advices people to take barbituates. Matilda and Bob try to inject as many people as possible as the predicted event gets close.

Giles returns to the building where he worked. The women who killed Alwyn is there. She says that Richard isn't a priest. He's fanatical about the end of the world and is killing people. Giles finds his fully grown daughters and Matilda, who's an ex-lover?

Oh, it's the first part of a trilogy. It has elements of SF and fantasy that don't always mesh - wouldn't small people have such high-pitched voices and such different ears that communication with normal sized people would be difficult. I like several of the ideas.

Other reviews

• echoesinanemptyroom
• potsandplots (The Expanded Earth contains two central stories. One is set before “the descent” (where humanity shrank), and the other is in essence a quest, where a disparate group of adults is shepherding a gaggle of children to safety. ... This quest aspect of the story is strangely reminiscent of Watership Down. ... The other thread offers an explanation of how the descent occurred. Hubris and science gone wrong. An eccentric scientist, their research derided, stumbles upon something incredible. This work is appropriated by people who don’t understand its significance, triggering a cataclysm. These events centre around Matilda, a paramedic, as she tries to cope with, understand and contain the initial shrinking outbreak. ... While these are the two main threads, there is a third strand that is arguably even better. A potpourri of stories from around the world, giving wider context to the tale and showing us glimpses of what is happening away from the main story )
• goodreads (3.83 rating; 1,015 ratings)