Demons (also known as The Possessed) is a novel by Fyodor Dostoevsky, first published in 1872. This psychological and political thriller delves deep into the complexities of human nature, exploring themes of ideological extremism, moral corruption, and the destructive power of belief systems.

Set in 19th-century Russia, the story revolves around a group of radical intellectuals who plot to overthrow the government, while grappling with their own personal demons and conflicting ideologies. The characters are intricately developed, each embodying various social and philosophical movements of the time, from nihilism to anarchism. Dostoevsky's masterful prose captures the internal struggles of individuals as they navigate the turbulent political landscape and their own inner turmoil.

At its core, Demons is a powerful examination of the consequences of rejecting traditional values and embracing radical ideologies without fully understanding their implications. The novel's intense psychological insights and profound philosophical questions make it one of Dostoevsky's most challenging and thought-provoking works.