The paper ” The Probabilistic Model Checker Storm” by Christian Hensel, Sebastian Junges, Joost-Pieter Katoen, Tim Quatmann and Matthias Volk has been accepted for the Journal of Software Tools in Technology Transfer. The paper presents the ins and outs of Storm, the model checker for discrete and continuous Markov models (with and without non-determinism) that has dominated the 2019 and 2020 tool competitions on probabilistic model checking.