Not the easiest book to read because it is not about the biblical text but a historical "conversation" between Paul Helm, the Vosian group and Richard A. Muller. Prominent in this conversation are Jonathan Edwards, who Dr. Muller maintains departed from the Reformed Orthodox in his determinism/compatibilism and Francis Turretin as a kind of representative of the Reformed Orthodox. Dr. Helm basically argues that the differences between Edwards and Turretin are stylistic rather than substantial. Edwards is not a scholastic theologian, while Turretin clearly was. Furthermore, Turretin as well as several other Reformed Orthodox theologians, hold to a point fundamental to compatibilism which is that the will follows the last judgment of practical reason or is determined thereby. Furthermore, they also argue that the will is never free FROM God, but is determined and governed by Him.
All in all, a good historical discussion, but not the easiest nor the best if one wants to understand what is the Reformed or biblical position on free will.