After living 45 years in Germany, the Turkish Hüseyin Yilmaz, seventy, announces to his family that he has bought a house in Turkey and they should return to make the necessary reforms. The idea is unwelcome and causes very heated discussions. In addition, Canan, a granddaughter of Hüseyin, announces she is pregnant and the father is her English boyfriend, and no one knew anything.

Journalist Rommy Kirchhoff wants to interview a whistle-blower. Paul Holthaus, lobbyist on behalf of the agricultural company Norgreen Life Inc., is ready to report on the background negotiations on TTIP. But as soon as the explosive interview begins, Rommy is overwhelmed. When she regains consciousness, there is no trace of the informant. Rommy realizes she has entered a story of unprecedented proportions.

The Viennese detective children Biggi, Patrick and Luke find a key in dragon form, and their curiosity is aroused. They realize that the sinister Lady Q is interested in opening the legendary moon palace and find the elixir which is believed that promises eternal youth. The Tigers must prevent that Lady Q enters into possession of the priceless liquid.