Johannes Klare is the senior, charismatic preacher of an unofficial, self-supporting fringe church in Stuttgart, aided by his devout, devoted wife Lydia and her ex-con cousin Bernd Trampe. Finding juvenile homeless busker Simon Rützel, who talked sense, by the way but refusing to be taken to hospital as ODd junkie, the childless couple take him in their home and start to think of him as a lost son. Rich parishioner Volker Reiche offers to privately finance the herd's dream of a community center, but Johannes grows suspicious of his agenda. Discovering Simon's homosexual nature, Johannes decides against throwing him out and must admit the exorcist is a gross bigot. In Lydia's weekend absence, Johannes succumbs when Simon rightly guesses he suppressed his own gay lust for years, but comes clean to Lydia, where-after Simon is driven to relapse and the couple seeks to rescue their lives and vocation after the 'mortal sin' gets known.