A stagecoach arrive sin town and an overweight woman, Kitten Twitty, gets off. She unloads a large bag and goes inside, while the local children laugh at her. She takes a room at the hotel and starts to go upstairs, and Jim West offers to help her with her bag as he comes down. He assures her that he's in the room next door to her and she'll be perfectly safe. Once he drops the bag off, Kitten asks him to stay but Jim says he was going across the street to get some shaving soap. Once he's gone, Dr. Miguelito Loveless emerges from the bag and the two of them laugh triumphantly.
Later, Kitten prepares a bowl of shaving soap while Dr. Loveless sits on the bed and eats chocolate. She warns him to stay off his leg, which he recently injured, and assures Dr. Loveless that she prepared the shaving water just as he ordered. Triumphant, Loveless boasts that he has finally devised a way to take control of Jim West's mind, and that the agent will believe whatever his mind tells him.
Seated in his wheelchair, Loveless watches through a one-way mirror as Jim enters his room and starts shaving. The doctor closes the shutter and boasts that he has accomplished far more with a shaving brush than the great tyrants of history. He then pours the remaining white powder into a vial and says that Jim has been given the maximum dose, and the veneer of civilization will be removed and the primitive murderous nature of man will be revealed.
As Jim puts his away his shaving kit, he suddenly grabs his head in pain, and then splashes some water onto his face. The pain hits him again and he dabs more water on his face before collapsing on the bed. He hears Dr. Loveless' voice and looks up to see the villain sitting on the windowsill. Before Jim can grab his gun, Loveless draws on him and boasts that he'll spare him for ten seconds. Jim rolls to the ground, grabs his gun, and shoots Loveless, who falls to the street below. Jim runs down to check the body and discovers that Loveless has vanished. A man comes over, directs Jim's gun away from him, and asks what the problem. None of the bystanders have noticed anything unusual. As he goes back to the hotel, Artie arrives on the stagecoach and greets his friend. He realizes that Jim is acting oddly, but Jim says that he's just suffering from a headache. As they go inside, Loveless watches them from the hotel balcony and laughs.
Back in his room, Kitten dances to the tune from a music box while Loveless explains that he can predict exactly what Jim will do, and that night the agent will shoot and kill Artemus Gordon.
In Jim's room, Artie suggests that Jim might be obsessed with Loveless given that the genius has escaped them three times. Someone has sent Jim a poster of Loveless with a note on the back asking him to meet in an abandoned shed so they can turn Loveless over. Artie says that the handwriting matches Loveless'. Jim has another searing headache and wipes his face with more water. When Artie offers to get a doctor, Jim admits that he's not feeling well, and he's not going to go after Loveless in his condition. Artie offers to check out the shed on his own, but Jim irritably insists on going with him. As they go, Artie points out that Jim has forgotten his gun, and Jim reluctantly picks it up.
Jim starts running to the shed and Artie warns him to stop since Loveless has undoubtedly set an ambush. They enter the shed but there's no sign of Loveless and only one door in. Artie tells Jim to go back to the hotel to tend to his headache, and Jim sees Loveless at the door, laughing. When Artie turns, there's no sign of Loveless and he's heard nothing. Jim tells Artie that that he can't handle Loveless on his own and snaps on him, accusing him of wanting to be the hero. Artie gets him to calm down and Jim apologizes, admitting that for a moment it was like he hated him. The two of them go back to the hotel. Jim uses more of the water as Loveless watches through the mirror.
That night, Jim goes back to the shed and hears Loveless' laughter echoing in his head. He goes inside and lights a lantern, and Artie tells him to put it out. Jim hears Loveless' laughter and tries to go out after him, but Artie stops him. When he refuses to get out of his way, Jim shoots him down. With his dying breath, Artie asks why and Jim stares in horror at what he's done. He runs out and hears Loveless laughing, and runs through the streets back to the hotel. Jim asks the clerk to call the sheriff, and explains that he shot his friend who arrived on the stagecoach that day. The clerk explains that the stagecoach didn't arrive that day, and Jim grabs him and insists that he met Artie. When he realizes the clerk is telling the truth, Jim runs up to his room but then collapses. Loveless and Kitten come in from the adjoining room and the doctor says that Jim may wish he's dead, but they won’t let him die for a long, long time.
The next day, Artie arrives on the stagecoach as scheduled. The hotel clerk tells him that they took Jim to the hospital the previous night because he went raving mad, waving his gun and claiming that he had killed Artie. The clerk is called away and Artie reads the poster he was sent from someone promising to turn Loveless over.
Jim wakes up in a hospital room and finds himself face-to-face with a portrait of Loveless. He manages to get up and finds Loveless, who offers him some sherry and boasts that his experiment succeeded. Loveless assistant Antoinette comes in and tells the doctor something. Jim feigns disinterest about the experiment, and Loveless can't resist explaining that he plans to kill every man, woman, and child in America.
Artie rides to the mental hospital where Jim was taken. He helps an invalid woman up the stairs, but the "woman" throws him to the ground. The "patients" surround Artie and Loveless and Antoinette arrive as Artie is held at gunpoint. They throw him in a room with Jim, who is relieved that his friend is alive. He realizes that Loveless made him think that he shot Artie, and that the doctor will use it on everyone in the country to force millions of people to kill each other. Artie points out that there's no way to distribute the substance nationwide, and Jim tells him to keep silent when Loveless returns, and the doctor will explain everything to them. When Loveless comes in, the two agents feign disinterest. Loveless has Kitten and Antoinette mix the powder with water and offers to demonstrate it on Artie. Jim admits that they're convinced, but doesn't believe that he can use it on millions. Loveless tells Kitten to serve the drug to the hospital staff in the wine. After Loveless leaves, Jim points out to Kitten that Loveless has ordered the death of 20 people just to prove a point. Kitten nervously defends her employer, insisting he's bluffing, but Jim warns that Loveless will kill her along with all the rest. She says that Loveless will make her pretty, but Jim tries to get through to her, warning that she'll be next. Kitten ignores him and leaves.
That night at dinner, Jim and Artie are escorted from their room directly into a cell with a dinner table. Kitten is there and Jim suggests she go to the dining room and watch 20 men and women tear themselves apart. She continues to insist that Loveless is having his little joke. Loveless and Antoinette come in, and start singing. Jim and Artie sit down to eat their dinner, and screams echo out from the dining room. The attendant holds it shut until the screams die away, while Loveless and Antoinette keep singing. Finally the doctor turns to the mirror and imagines himself as a giant, boasting that he is invincible. He has Kitten open the door and confirm that the staff is dead, and she recoils in horror. Loveless then explains that summer can never come, and that he will spread his drug via water. He shows them a duck and explains that he will release thousands of them, each with a pellet of the powder on its leg. Once he has destroyed America, he will travel the world and bring a new age.
As Jim and Artie are lead out, Jim steals a turkey leg. Back in their room, he tells Artie to start eating while he comes up with a plan. Once he's done, Artie sharpens the bone while Jim rigs a slingshot from their suspenders and a chair.
On the nearby lake, Loveless collects some of the ducks to take to his lab.
When the attendant comes in, Jim and Artie shoot him with the bone and take his gun. They go into the cage but the lock is too strong to shoot off. Kitten is seated in the room, in a state of shock, and Jim calls her over. He says that she has to let them out, and that Loveless will sacrifice anyone, including his own people, to get what he wants. Kitten defends Loveless, saying that he only exposed what they really were, and can make anyone pretty. She insists that Loveless understands her and imagines herself in the mirror as a beautiful woman. The agents concede that Loveless can do what he says, but points out that there will be no one to appreciate her in the new empty world that Loveless will create. Kitten can't bring herself to open the door and betray Loveless, but she collapses, sobbing, and pulls apart the bars in her emotional turmoil. The agents slip out, and Antoinette arrives as Kitten realizes that she has betrayed Loveless.
Loveless is preparing the ducks for release, reassuring them that hunters will no longer kill them. The agents sneak in and find some of the pellets, and watch as Loveless grasps the lever to release the ducks. Jim draws his gun and warns him to stand down, and shoots the rope connecting the lever to the release mechanism. Loveless flees while Jim holds the weight long enough for Artie to brace it. Loveless, Antoinette, and Kitten flee to the lake and get into a rowboat, and try to escape. Jim and Artie go after them and Jim fires a shot at the boat. It springs a leak and starts to sink. None of them can swim and Loveless assures Antoinette that they will live forever as they go beneath the water.
Ten minutes later, Jim searches the lake without success. Artie insists that Loveless must be dead, but Jim isn't so sure. They admit that they'll miss the little man with a giant rage against the universe and leave... unaware of the two large bubbles forming in the middle of the lake.