Continuity mistake: When Vorenus ask Eranus where his children are, Vorenus raises both his arms. When it cuts, they are down.
Factual error: Cicero's secretary, Tiro, is seen throughout the series wearing a plaque around his neck marking him as a slave, and here Cicero tells him, "You've been freed in my will". However, Tiro was freed in 53 BC, several years before the events depicted in the series.
Answer: The show became too costly to produce so they ended the season early to save money.
Shannon Jackson