The plot of Train To Busan is a fairly simple one: A father by the name of Seok-woo is taking his daughter Su-an to see her mother in Busan for her birthday, along the way, the train, in fact the entire nation of Korea, becomes plagued with zombies.
We see glimpses of the impending doom, but nothing concrete until Seok-woo and Su-an arrive on the train and our eponymous journey begins.
As the passengers board, we catch glimpses of a stowaway hop on before the doors close, a college-age girl, by the looks of her. She takes refuge in a bathroom to bind her injured leg…which includes a bite wound.
Meanwhile, we follow Seok-woo (Who decides to take a nap) and Su-an, who wanders off to find a bathroom.
This is where the tension starts to build, as we know the bitten girl will turn, we just don’t know when. Su-an tries a few bathrooms, but finds them occupied, one by a homeless man (Who I’ll just call Homeless Guy), and another by a pregnant woman, while her husband, Sang-hwa (Dressed in a blue suit) stands guard and directs Su-an to the bathroom at the other end of the car.
Though we’re led to believe she might, Su-an does not stumble upon the bathroom with the infected girl.
However, someone does. A train attendant named Min-ji finds her unconscious, before she breaks out into a twitching fit. Min-ji calls to her supervisor about the situation, but, it quickly proves too late for anything to be done.
The girl gets to her feet and, as zombies do, bites the first person she sees, in this case, Min-ji. Min-ji quickly turns and things rapidly worsen. As this is happening, TV broadcasts on the train begin showing rampant violence across Seoul and other major cities throughout Korea, foreshadowing the increasingly deteriorating situation on the train.
As one might expect, the zombies quickly begin to multiply and overrun the cars, with several of them now cutting the passengers from safety.
While things escalate on the train, things get progressively worse across the country. As the train approaches its first stop at Daejeon, the conductor informs the passengers they will not be stopping there and they quickly see why: A crowd of desperate people at the platform beg for sanctuary on the train, but a mob of zombies soon catch up to and devour them.
As they pass that horrific scene, most of the survivors try to quarantine themselves from the horde, where we get some interesting scenes about the nature of morality and self-preservation in a time of crisis, but, I’ll cover that more in my “Characters” section later.
Eventually, the conductor is informed that the train has been ordered to stop at Cheoson. While most of the passengers believe they’ve finally been saved, Seok-woo is told by a client of his in the military that they’re due to be sent to quarantine and he advises Seok-woo to go a different way and meet with his unit instead.
Sadly, there is no safety. The army has already been turned.
As it becomes obvious the city is lost, the conductor is forced to start moving the train, lest they be swamped by the horde. What follows is a harrowing scene where Seok-woo, Su-an, and several others must run to reach an open car before the zombie army catch up to them.
Eventually, Seok-woo, Sang-hwa, and a high school baseball player named Young-guk desperately trying to pass through zombie-infested cars to reach Su-an, Sang-hwa’s wife, Seong-kyeung, Homeless Guy, and an elderly lady by the name of In-gil and bring them back safely.
While they succeed (With great difficulty) the welcome they receive from the other passengers is not a warm one. With one passenger in particular leading a panicked mob to first try to keep out Seok-woo and company, then expel them to the baggage car. They succeed in doing so, but, it doesn’t save them.
Eventually, the conductor discovers that their path to Busan is blocked at the next station by a pileup of wrecked trains.
As the conductor tries to find a new car to take his remaining passengers to Busan, Seok-woo and the remaining survivors grow impatient and follow him. The horde quickly does the same.
Though the conductor doesn’t make it, he does get an engine started, and it does manage to carry a few passengers, but, they’re not out the woods. The infected follow them, and by the time the train reaches Busan, only two of our train passengers survive.