The Norse berserkers were wild warriors of Scandinavia known to enter a trance-like state that allowed them to fight with increased strength and a rage that granted them immunity to many forms of harm in battle. Though many theories have been advanced as to the cause of this state, the most widely believed is that the intoxicating mushroom Amanita muscaria was used.The following article underlines the issues with this theory and provides an alternate intoxicant that fits with the reports of berserker behaviour much better: Hyoscyamus niger.Literature from a variety of disciplines pertaining to history, toxicology, pharmacology, and botany was compiled to frame and support the argument.H. niger proved to be a more likely intoxicant used to induce the berserker rage state.With its anticholinergic tropane alkaloids and symptom profile, H. niger is a much more likely cause of the berserker state than A muscaria. Though there is not enough archaeological and historical evidence to prove or disprove this theory, it provides a novel explanation that is at present the most viable means of understanding the berserkers' trance.