Oscar Pistorius and his girlfriend Reeva Steenkamp had an argument, leading the athlete's model girlfriend to run away and scream so loudly in terror the neighbours could hear, the prosecution has alleged.
The balcony door, which the Paralympian has repeatedly alleged was used by him that evening to bring in a fan moments before he heard movements in the bathroom, was "never open", prosecutor Gerrie Nel told the murder trial in Pretoria. This is the "only reasonable" inference.
The prosecution has attempted to prove inconsistencies in Oscar Pistorius' version of events
Unveiling a picture of the fan blocking the entrance to the balcony, Nel said to Pistorius: "Your version is a lie".
Pistorius has denied he intentionally killed the model and reality TV star, and argued that he believed her to be an intruder.
"Now we have to find the policeman who put it there," Nel said, alluding to the number of occasions the defence has suggested the crime scene was tampered with. "It was moved when you and the deceased got into a disagreement.
"A policeman must have been clever enough to move that fan just back into the door to make your version impossible."
In a cross-examination that was attempting to prove inconsistencies in the athlete's memory of the night, Nel pointed out the place where the fan was in the picture was in the same area Pistorius had put his prosthetic legs, making it impossible for him to have got past.
If the fan was were Pistorius said it was, Nel said, the cord would not have stretched to the plug on its extension lead. 'Keep trying Mr Pistorius, it's not working. Your version is so improbable, no-one would ever think it was true," Nel said.
Pistorius had earlier described how he heard Steenkamp say nothing else after she said: "Can't you sleep, baba?" when he got up to take the two fans from the balcony.
He did not hear Steenkamp move out of the bed to the toilet, he said. "I don't know when she got up. I wouldn't have seen her because she was behind me. I had the fans blowing in my face."
It was also pitch black in the room, he said, because he had thrown a pair of jeans over a blinking LED light.
Shown a picture of room which had a duvet lying on the floor, Pistorius said the duvet had been moved since he shot Steenkamp, that neither he nor Steenkamp had left it on the floor, and that he had seen the silhouette of the duvet on the bed and assumed his girlfriend was underneath it.
Tearful and trembling, he earlier admitted that he had "no reason" to shoot that night, and if Steenkamp had spoken, he would not have fired. "My firearm was pointed at the door because thats where I thought someone was," he said.
Pistorius also told the court he did not believe that Steenkamp had eaten after the pair ate chicken strips and stir-fry vegetables for dinner, eight hours before her death. The court's pathologist has said Steenkamp ate a maximum two hours before her death.
On Thursday morning, Nel tore into the runner after he denied his finger was "on the trigger" when he fired a gun in a crowded restaurant.
He was also pressed on how he had treated Steenkamp during their four month relationship, with Nel insinuating he had been controlling and uncaring.