Directed by Tanay Genco Ulgen. With Stefan Morawietz, Denis Lyons, Kathrin Hhne, Bartholomus Kowalski. Once Jack Walker was Germany's greatest action star, the hero of countless Germanic martial arts and action adventures, women wanted him and men wanted to be him, the world was his for the taking and he was the King of the action genre, filling cinemas with his adventures onscreen and the tabloids with his adventures off-screen. But success can be a fickle mistress and over the years its turned…