Regensburg is looking forward to the upcoming German Catholic Day. 100,000 visitors are expected. The anticipation is cut short when a monk's body is found. Finding place is the substructure of the stage, which is set up for the opening service. Inspector Lucas and her team immediately start investigating, because one thing is clear: the opening must not and should not be postponed. Her first lead leads her to the influential "Exercitus Sanctus Jesu" order, which is controversial among lay Catholics - mainly because of its opaque banking transactions. The monks of the order, under the leadership of the Superior General, are hiding something, it becomes immediately clear. While the investigators are researching on site, the situation worsens.
In an anonymous email, the cancellation of the opening service is requested, otherwise there will be a catastrophe. The connection between the dead man on the cathedral square and the blackmail is obvious. Ellen Lucas, who makes no secret of her rather church-critical attitude, gets into a fight with Boris Noethen.Because he is trying, not least out of religious conviction, to prevent a possible cancellation of the Kirchentag, which is in the spirit of Andreas Schneiderhahn, the organizer of the Kirchentag. Since the blackmailer's email also calls for the opening of all church property for refugees, a group of Catholics who are involved in church asylum come into focus. With the help of Tom Brauer, Ellen Lucas finds out that Martina Heise, a woman from this circle, definitely has a motive to take revenge.
But new suspicions also arise in relation to the "Exercitus Sanctus Jesu" order, and Brother Peter, a monk who was very close to the dead man, disappears. Then, in another anonymous email, no less is demanded than the distribution of the entire church property to the poor. An attached quote from the Gospel of Matthew is deciphered by Inspector Lucas and puts her on the right track. But it's about much more than a theological riddle, because the blackmailer is in possession of a large amount of explosives.

Andy Wolf, manic journalist and author of numerous bestsellers on conspiracy theories, visits Inspector Lucas again in her police station. He offers her a deal: she'll help him with his latest research and give him access to the police database, in exchange for him giving her tips on how neo-Nazis are getting weapons from underground weapons storage facilities. Together they would be unbeatable. Lucas brushes Andy off – a weirdo, harmless. Hours later, Andy Wolf's top floor apartment in Regensburg was ablaze. When a burning man falls out of the apartment onto the terrace of the "Camerota" restaurant, the fire becomes a case for Inspector Lucas - who acts with a guilty conscience because she had not taken Andy seriously.
But in the pathology it turns out that the dead man is not Andy, but his co-author Florian Reichelt. Florian Reichelt did not agree to Andy Wolf being paid and threatened to sue him for a sum that threatened his existence. The dead man's pregnant widow, Suse Reichelt, confirms this motive. Andy Wolf has gone into hiding and is on the wanted list . He hides in the "Camerota" restaurant with its owner, the old leftist Daniele Grasso. Andy Wolf makes conspiratorial contact with Lucas. Lucas agrees to a deal with him and – despite a search – lets him go again. Through Wolf, Lucas finds out that there was in fact a historically documented NATO "Gladio" program in the 1950s, in which secret weapons caches were set up.
The weapons and explosives stocks of the local neo-Nazi scene probably come from this camp. Then an attack is carried out on Andy Wolf, who from then on lies in a coma with serious injuries. Suse Reichelt takes care of Andy in a remarkably maudlin way. Did she have a relationship with him, is jealousy a possible motive? With regard to the weapons finds, Johannes Conrad, who has access to the "Gladio" depot, is increasingly becoming the focus of the investigations. Johannes plans a bomb attack on the Kelkheimer Halle, a war memorial symbolizing reconciliation and peace. In a spectacular operation, Lucas and her team manage to prevent the attack at the last minute. But is Johannes also responsible for the assassination attempt on Andy, and is he the killer of Florian Reichelt?