In the work before you, Dr. Umar Al-Ashqar, a well-known contemporary scholar of Islam, has attempted to tackle two important topics. The first topic is that of the characteristics of the jinn. This is a difficult topic for many reasons. One of them is that the devils are known to be liars. Thus, even when a person does encounter them, he cannot put much trust in what they claim about themselves. Therefore, one must virtually rely only on the statements of the Quran and the authentic hadith of the Prophet (peace be upon him). The second topic is the characteristics and methodology of Satan himself. It is no coincidence that Allah has mentioned Satan, his goals, his plots and his allies throughout the entire Quran. This is because Satan is man’s greatest enemy. The believer must know the key to defending himself from Satan.