John McClane was losing his mind.
Since the incident at Nakatomi Plaza, his life hasn't been the same. After the reporters and the news cameras left, it wouldn't stop. The incidents. When he took his wife and daughter camping, John noticed something strange about the campers up the trail. They turned out to be eco-terrorists hatching a plot to poison the forest with radiation (except they really turned out to be working for a real estate mogul trying to buy up the land). John had to fight for his life. Again.
Three days later on Career Day, a group of white supremacists took over his daughter's school, threatening to release the Plague (except really it was for nazi gold buried under the gym.) A week after that, a street gang seized his wife's Fun Run For Breast Cancer (princess in exile). McClane didn't want to leave the house anymore, and started to drink again.
His daughter's birthday was coming up, and he couldn't let her down. Terrified, he ventured to the mall anyway. As soon as he spotted the prison tattoos on the guy at Orange Julius, he knew it was a mistake. He tried to look away, only to see another felon at Sbarro. And another at Panda Express. When they started nodding to each other, he knew whatever their plan (hold the mall hostage for ransom), and whatever they really wanted (diamond encrusted chihuahua sculpture), it was about to hit the fan.
John McClane was losing his mind.