Canyoning is another popular activity in the Alps, but it isn't for the faint of heart. In a glorious natural setting, the group faces some tough passages and harrowing jumps over waterfalls.

Katja and Dirk arrive in time to stop Mr. Petri's madness and bring him in to the station. Meanwhile, Lothar finds out the truth about their supervisor.

Germany is not a big enough country to devote all of its land to creating renewable energy – but there is another place with vast expanses of empty space and limitless sunshine.

Whitewater rafting and kayaking are very popular but also very dangerous sports in the Alps. Here we see some remarkable footage of a few daring individuals making their way through the thundering rapids.

Henning finds a potential lead regarding the runaway boy's identity, while Petri turns up at his former workplace yet again – this time armed.

In this segment, we finally glimpse the peak of the Großvenediger. Back down in the valley, families make hay without the usual farm machinery.

Henning shows up at Harry's to discuss the problems he's experiencing in his relationship, and is disappointed when Harry expresses the same opinions as his girlfriend. Then the doorbell rings...

In this segment, we visit quaint settlements, a chapel carved into a rock, and a waterfall that seems to disappear into the earth, all at the foot of some of the tallest mountains in Europe.

Walter Petri refuses to believe that one of his designs could have been flawed, and is furious at his wife for talking with the company's boss behind his back.

In this video, physicist and author Harald Lesch talks about how Germany could phase out coal and nuclear power completely and still meet all of its energy needs.

At the station, the group tries to figure out whether Küppers is actually pregnant and where the young runaway came from. When Walter Petri returns to work and locks himself in his former office, the real reason for his early retirement is revealed.

At home with Harry, the runaway finally speaks. Meanwhile, Walter Petri follows Dirk's advice and returns to his former office – but he doesn't like what he finds there.

In this segment, we explore the beautiful landscape around the Staller Saddle mountain pass, visiting alpine roses, a pack of magnificent stags, and a traditional tavern where local farmers carry out their negotiations.

After Henning's mistake, the group finds the young stowaway hiding in a dumpster. Meanwhile, Lothar uncovers new information about Superintendent Küppers.

Harry and Henning are called to the harbor, where a young stowaway has been found on a ship that was leaving for Sweden. Henning takes a personal call, during which the young stowaway disappears.