The Great Book deals in depth with the fourth noble truth, the path that leads to liberation from suffering. It is not a path that appears difficult, let alone impossible, although as we shall see, it is easy to get lost and become irretrievably bound to unbearable conditionality. 
We start with the correct belief. It is evident that if we start from wrong axioms, everything that comes later will be wrong and there, from the beginning, we will be lost. The erroneous beliefs are so many and so varied that we can say that they are all of them, except the correct one, which is only one. It is an incorrect belief that all paths lead to liberation. The correct one is that all paths but one bind to Samsara and within it, even to hell. 
Right belief is an accurate conceptual understanding, based on listening to the teachings and logical reflection on their meaning that leads to the right disposition, to putting the conditions in place to carry out the effort, which is the second factor. It is of little use to have the right belief if there is no disposition. Lack of disposition or incorrect disposition is another way of getting lost. 
 Right belief subjected to right thinking leads to right speech, right action and right conduct. Right speech is essentially not lying. To lie is to kick an uncomfortable situation forward, which you will always find yourself back to again corrected and augmented sooner rather than later, so it is unwise to tell lies. 
The right action is to avoid evil, because every bad action brings a bad consequence. But right action is not doing good, not least because good actions often have even worse results than bad actions. Right action carefully evaluates the outcome of actions so that the results are not harmful. 
Right conduct consists in avoiding acting out of any of the three underlying tendencies, craving, aversion or ignorance. Right conduct properly applied is the way to behaviorally eliminate the roots of suffering. 
This path is laborious and requires great effort on several levels, applying it to the correct remembrance of the instructions of the practice leads to right contemplation. 
Not making an effort leads to getting lost. But also the misdirection is a consequence of not knowing or misunderstanding the instructions of the practice. If one has a wrong idea of the instructions of the practice, the effort applied will forcefully push away from the direct path to failure. 
However, applying the right effort to execute the right instructions of the practice leads to right contemplation. And with contemplation we gain access to gnosis, to the paranormal abilities and therefore to the episteme that constitute right wisdom and this to right liberation. 
And not only that, right contemplation transforms, endowing the practitioner with ethics. He will no longer do anything moved by underlying tendencies, nor will he lie, and he will correctly assess his actions by limiting the consequences. Thus the sumum bonum of the teaching, Nibbāna, is achieved by being able to uproot the factors of clinging to existence and abandoning the bondage of Samsara. 
No less important are the Discourses intertwined with the Factors of Enlightenment containing 184 discourses on the seven factors of enlightenment which are the qualities that lead the meditator to enlightenment. 
The Discourses Intertwined with the Practice Instructions contains 104 discourses on the four kinds of practice instructions, explaining clearly and simply how the practice on the breath addresses them all. 
The Discourses intertwined with the Faculties contains 178 discourses on the five faculties of faith, effort, practice, contemplation and episteme. This booklet is expanded with discourses on 22 other faculties. 
This book also addresses Right Efforts, the Five Powers, the basics of Paranormal Abilities, and psychic powers and jhānas. 
The Ānāpāna Saṃyutta or Discourses Intertwined with the Practice Instructions on Breathing contains 20 discourses on breathing meditation. This development fulfills the four practice instructions and the seven factors of enlightenment. 
Finally, the Great Book deals with the Entry into the Stream and the Four Noble Truths: Suffering, its origin, its cessation and the Noble Eightfold Path. These formed the main theme of the Buddha's first discourse at Benares.