Short answer: what Marx argued is specific to communism, why our past sketches of communism aren't capturing it, and how we need to retool our concepts & systematise in a very different kind of way to do so.

Longer (highly provisional) answer:

1. In chapter 1, the book sketches nascent critiques of capitalism among Marxists along distributional, teleological, dominational & value-critical lines, and attempts to formalise the latter two approaches without taking a specific stance on the nature of the good or relative weights of critiques.
2. In chapter 2, the book conducts an immanent critique of proposed & past planning schemes (with special attention paid to the Critique of the Gotha Programme, Anti-Dühring, Stalinist material balance planning, Albert & Hahnel, post-Lange-Lerner-Taylor schemes, & Cockshott & Cottrell).
3. In chapter 3, the book examines the philosophical & political ramifications of this kind of value-abolitional pessimism, against the relief of Mao, contemporary liberal ideal political theory (in particular as it stems from Gerry Cohen), and some work by the writers of Endnotes journal.
4. In chapter 4, the book proposes an ontological grounding of Marx's concepts, & value more specifically, with regards to real abstraction, form-determination, emergentism, pragmatism, & scepticism.
5. In chapter 5, having deflated the conceptual underpinnings of the abolition of value, the book demonstrates the actualisability of the negation of value, and holds up this conception against value-abolitional pessimism.
6. In chapter 6, the book takes up again the dominational critique of capitalism with regard to republicanism, selected ultra-left literature, & Adorno; systematises it, argues for its irreconciliability with the value-critical approach, & attempts to show how a specifically instrumentalised conception of the dominational approach is either self-defeating or collapses into the value-critical approach.
7. In the afterword, the book suggests a set of tractable problems for the actualisability of the value-negational approach, proposes some solutions to these problems, and sketches a minimal research programme for communism.

As you may know, I just quit a job to finish writing a book on communism. I've been working on this book for a good while now, and I have a clear outline of what precisely remains to be written. I hope (fingers crossed) to deliver a final proposal within 3 months, and a first draft manuscript within a year.

I am writing this book without institutional support of any kind. Most left & academic publishers pay authors little to nothing. In practice, most authors get remunerated for writing these books through tenure. I have one going concern which motivates the top-line amount I'm trying to raise: health insurance. My last job had health insurance uniquely well-suited to my medical needs, which continuing via COBRA will cost ~$900 a month.

At the lower tier, you get at-least-weekly (though likely cursory) updates on the writing of the book, as well as the occasional finished sub-section (not in chronological order), and membership in a forum for chatting on the book!

The higher tier is a little like pre-ordering the book, though not exactly. Its price, over the course of the year I'm going to be doing this, is set to be about the cost of buying a copy of the book. As such, I'll get you a complete copy of the book proposal and a more or less complete first draft manuscript. I'll also try my utmost to get you an author's copy of the final book, although as the book hasn't been sold and publisher policies on author's copies are variable, this is a somewhat tenuous promise, and worst-comes-to-worst may culminate in my just buying you a copy off Amazon.