Amaranth

For fans of Hugh Howey's Silo, and the TV series The Last of Us
An underwater ark.
An incurable disease.
Two passengers to save them all.
The Flood swept across the world over a century ago, sinking entire cities and the triumph of modern civilization. Aboard underwater arks, the survivors have been preparing to return to the Surface, under the benevolent eye of their Creator. But the ship's commander seems to have other plans for them.
Skyler Goldberg has only two years under his belt as a doctor at Med Bay, yet he must stop a deadly disease from wiping out the last survivors. Imaginary beings they call Fairies drive infected people's minds to madness. With an unshakable hope in humanity's salvation, Skyler will sacrifice everything to save them.
The Ark's prison is filled with prisoners that are either dangerous, mad, or both. Emily Bates makes it her mission to guide them back to reason through unconventional interrogations. Thanks to her ability to sense their auras, she can see right through their lies. But when she handles a case like no other, what she sees terrifies her. Little does she know that their days on the Ark are numbered.
Are you ready to board the Ark?