It was just a wish:
Mother, brother, home, and love.
Heroes pay the price.
Looking for missing people in Illinois, Sam and Dean realized that they were hunting a djinn. Learning from Sam’s research that djinn lair in large ruins, Dean did a quick solo check of a deserted warehouse, only to be attacked by the djinn – and wake up in what seemed to be the world he would have wished for, a world in which his mother hadn’t died and the Winchesters hadn’t become hunters. Cautiously exploring, Dean soaked up every sweet and normal thing: his mother, alive, well, and loving; Sam safe, innocent, happy, and newly engaged to Jess; photos recording a whole lifetime of family events; a loving and understanding girlfriend. Even where pain intruded, it was bearable – smiling, softball-playing John Winchester had died of a stroke in his sleep, a peaceful and painless end, and while it hurt that Sam was largely a stranger, Dean was convinced that he could make things right. Except – he kept seeing a haunting and out-of-place girl, and when the evening news commemorated the anniversary of the plane crash that he knew he and Sam had prevented in Phantom Traveler, he turned to the Internet to learn that everyone whom the Winchesters had saved was dead, because they hadn’t become hunters. He knew what the father he remembered would have said, weighing his happiness against others’ lives, and so he set out to hunt down the djinn and get it to send him back. Accompanied by an incredulous Sam, he returned to the warehouse and found the girl of his visions strung up, being slowly drained of blood and life by the djinn. Only then did he realize that he must be in the same condition, with everything he was experiencing taking place only in his dreaming mind. Despite the pleas of his own desires, wearing the faces of his brother, his mother, his lover, and Jess, he stabbed himself, betting that dying in the dream would force him to wake in the real world. He found himself hanging in the warehouse with a distraught Sam trying to rouse him and cut him loose. The djinn attacked Sam, Dean broke free and managed to kill it, and the brothers found they were still in time to save the girl. Dean told his brother what he’d experienced and confessed how hard it had been for him to leave, while Sam tried to convince him that the lives they saved made all their bitter sacrifice worthwhile.
That bald summary doesn’t come close to telling the tale. This was Supernatural at its very best, exploring the soul of Dean Winchester and the self-sacrifice at the heart of a hero, even the most reluctant one. Raelle Tucker’s script, Eric Kripke’s direction, Jensen Ackles’ and Jared Padalecki’s performances, and the entire production design – from lighting to music to props and beyond – displayed a sensitivity and attention to detail that brought everything to life.