At the beach party there's a chain reaction (as the title of this episode implies), but this time no dead bodies are involved.

The truth comes out, and, even though Sianelli is dead, he's able to say something important through pictures.

We're getting very close to solving the case! The night is a long one for Lara and Luca, what with questioning Calcaterra and going on a search for evidence.

Luca and Lara question the tanner, and find out some interesting facts about Calcaterra, the gardener, but are no closer to solving the crime. The victim's wife shares her worries with Luca, and Lara and her aunt hear some strange noises in the garden.

After the fire everyone gathers in the commissioner's office, to discuss the situation. When Lara and Luca get left alone, they try to sort out what happened...

So much excitement in just a few moments! Lara and Luca let their true feelings get the better of them, and...

It may not come as a surprise that Toscani, after hours of ruining his eyes looking at the footage, does indeed find something strange. Unwittingly, and indirectly, he also saves the life of the Cine Service owner.

At police headquarters, a suspect gets questioned, but Manara isn't totally convinced. When conversation between Luca and Lara starts getting personal, Toscani walks in...

There are irregularities in this case, and as both Manara and Rubino know, that's where you look!

Luca and Lara go to question the tanner. He's not as forthcoming as they would have liked, but Luca, true to his nature, breaks the rules once again.

Zia Caterina might have found herself a gardener/handyman, and Luca and Lara locate the reels of film left by the film maker.

The police find the missing jeep and filmmaker, but what initially looks like an accident has some strange aspects about it.

Manara isn't happy about his boss's decision, but there's no time to sit and complain. If he can't take time off, no one can (and that includes Lara who's on a boat with Massimo)!

Manara is all excited about going home to Catania for a week of vacation, but do we really believe that he'll be allowed to leave?

This episode comes to a close with a pizza party at sunset among Lara's colleagues. Certain people are able to see a beautiful green ray in that sunset, making the famous legend come true.