DS Ronnie Brooks, DS Matt Devlin and DI Natalie Chandler investigate when a homeless man is found beaten nearly to death in the park at the centre of a well-kept square. As they dig deeper, they discover that the man tormented some of the local residents, giving several people a motive for violence. A respectable resident of the square is arrested, but Senior Crown Prosecutor James Steel fears that the jury will sympathise with the alleged attacker and, by acquitting him, encourage vigilantes.

The CSIs investigate a brutal murder after two office-mates plan to rob a casino. Elsewhere, Ray is forced to face up to his past in the light of his DNA results.

When a naval commander is murdered, an old friend contacts Gibbs. His friend, now a senator, believes he's being framed because of his connection with the commander.

A number of apparent suicides are linked to a sinister game of Russian roulette. Can the agents put a stop to the sick practice?

As Hitler drives Germany to the brink of destruction, German officer Claus von Stauffenberg leads a conspiracy to assassinate the increasingly crazed Fuhrer.