Following the events of The Sheriff and the Satellite Kid, Sheriff Hall and H-725 (using the official identity of Charlie Warren) still get no rest from the military - because the little alien has not yet grasped the meaning of keeping a low profile. They are constantly on the move, and H-725's father has had to pick them out of a tight spot too many times already.
Returning from Switzerland to Rome, the boss prof. Salviati, called 'The Prince', finds his business compromised by Rudy, a small local bandit full of presumption, audacity and men ready to kill. Commissioner Baldi a young and brave employee, will fight against them with the help of an ex-employee Rampelli.
Half-breed Keoma returns to his border hometown after service in the Civil War and finds it under the control of Caldwell, an ex-Confederate raider, and his vicious gang of thugs. To make matters worse, Keoma's three half-brothers have joined forces with Caldwell, and make it painfully clear that his return is an unwelcome one. Determined to break Caldwell and his brothers' grip on the town, Keoma partners with his father's former ranch hand to exact violent revenge.
Nico Palmieri is a police inspector who battles a criminal gang terrorizing a sleepy Italian town, extorting cash from the local merchants. With the threat of violence, no one dares to act, except for a restaurant owner who is forced by Palmieri to tell the truth.
At the beginning of the 1913 Mexican Revolution, greedy bandit Juan Miranda and idealist John H. Mallory, an Irish Republican Army explosives expert on the lam from the British, fall in with a band of revolutionaries plotting to strike a national bank. When it turns out that the government has been using the bank as a hiding place for illegally detained political prisoners -- who are freed by the blast -- Miranda becomes a revolutionary hero against his will.
Seven masked bandits, whose chief calls himself "Mormon", kidnap young Susy, cousin of the mayor of Clayton City, Frank Clonny. Frank accepts the $15,000 ransom requested by the bandits and thinks of a plan which will permit him, with the help of Benson, the sheriff, to free his cousin, recover the money and capture the outlaws. The plan, though, is destined to fail, because one of the mayor's men, Donovan, allows the bandits to escape the trap. Benson then decides to call in Sartana, who the Mormon immediately tries to eliminate with the help of four killers: Buffalo, who kills with a bullwhip; Martinez, an expert knife thrower; Sullivan, a giant of incredible strength and Silky, a sly and fast gunslinger.
Fernando returns home from his self chosen exile in Texas to get revenge for the death of his siblings. Instead he tries to start a revolution against the despotism of the landowners, but his relationship to his old friend Cipriano, who had turned in the meantime to a simple bandit, destroys his plans.
Ramon's parents are killed by men of landowner John Barrett. While trying to get revenge, Ramon is wounded but has saved the life of Rezza, an old disillusioned killer. While nursing his wounds, the men become reluctanfriends and Rezza teaches Ramon the art of shooting, surviving and the loneliness a killer has to bear. Ramon becomes threat for Barrett, the landowner engages Rezza to kill Ramon.