Lola, Nevin, Paul and Kikko are at a loss: where is their computer teacher, Professor Krupnik? He disappeared overnight without a trace. In search of their teacher, the children use internet software developed by Professor Krupnik, with the help of which they go on a virtual journey through time. They delve into the past and meet outstanding personalities in world history. An exciting, but not entirely safe, tour through the global data network. Always on their heels is a hacker who wants to manipulate the course of history with the help of two dangerous online agents. A challenge for Lola, Nevin, Paul and Kikko?