In the year 133 AD: Magnus and Finn set off across the Alps to visit their old friend Rocko. But when the two friends arrive in Rome, they face a nasty surprise: Rocko has been arrested - despite being rich and famous as a doctor and even taking care of a gladiator. Who is behind this? What do the mysterious signs on the front doors mean? And what is the password for the Colosseum? Luckily, the kids also run a delivery service called "cena celeris," meaning "quick dinner": The smell of warm flatbread opens many doors - because even criminals get hungry!.