SoKo Erfurt [CSI Erfurt]

You are members of a special commission set up today. Ever since the mayor of the city received a threatening letter early in the morning, everything in Erfurt has come to a standstill. An unknown threatens to carry out an attack, demands a gigantic ransom and claims to have a hostage in his power. Your task is to clear up the case as quickly as possible, avert the danger and find the author of the threatening letter. Can you make it before the perpetrator carries out his threat?