Can we know what the subject of each book will be?

The first: philosophy (proofs for the existence of God and arguments for Jewish religious commitment).
The second: Jewish thought. A general look at why there really is no such field.
The third: Jewish law and meta-Jewish law. A new look at Jewish law and its methods (first- and second-order halakhic rulings, changes in Jewish law, Jewish law and morality, authority and autonomy, methods of halakhic ruling, Jewish law and the state, leniency and stringency, etc.).

For those interested: basically everything can already be found in the articles and posts here on the site. True, in a more condensed form. But you can already read it.