There are people who are lonely.

Then there are people who slowly become invisible, even to themselves.

Tristan Brennan is twenty-nine years old. His days repeat with mechanical precision: waking before sunrise, riding the same buses, photographing strangers, editing videos for clients he'll never meet, and returning to an apartment that feels less like a home and more like a waiting room.

But routine has a way of hiding fractures.

As time begins to lose its shape, memories bleed into the present, reflections stop feeling trustworthy, and an impossible figure appears. A man who looks exactly like Tristan... but carries himself like the person Tristan could have become.

What begins as quiet conversations slowly turns into a confrontation with grief, guilt, fear, and the choices that imprison us long after the past is gone.

ISO is a slow-burning psychological novel about isolation, identity, memory, and the quiet war between the person we are and the person we refuse to face.