The cases presented in the brochure are so fantastic that no less fantastic and bold hypotheses are required to explain them. We are talking about the so-called poltergeist - incomprehensible phenomena accompanied by the spontaneous movement of objects, voices and knocking coming from nowhere, spontaneous combustion, etc. This issue of “Question Mark” tells about what is known about poltergeists today, the most common and interesting hypotheses. .The text of the book was translated from the original language using an artificial intelligence program. For the most part, the translation of the text is of very high quality, but in some cases, due to the imperfection of the technology, there may be incorrect phrase translations in the text, as well as single words and expressions may not be translated.