2. Episode 2

Birgit's brother, Wolfgang, grows frustrated by the lax approach to the case, particularly as it pertains to a person of interest with a criminal past.

3. Episode 3

As Wolfgang and his associates delve deeper into Kurt-Werner Wichmann's life, they discover a pattern of dark, disturbing violence that spanned decades.

4. Episode 4

Despite discovering a key piece of evidence, the truth about Birgit's fate remains elusive, but Wolfgang and his team remain resolute in their pursuit.