Vietnam also works backward in time, beginning in November 1971 and moving toward the day of Nicks birth.
The opening scene finds Jack in Vietnam, being transported to a new camp.
We learn, immediately, that hes ascended to staff sergeant and that hes entering unfamiliar territory.

Credit: Ron Batzdorff/NBC
Through his eyes, we see someone he recognizes.
Hello, little brother, he says though we dont even see Nicks face.
And backward we go.
Vietnam quickly does away with that illusion.
But day turns to night, and a crisis averted turns to a crisis unfurling.
We hear a bomb go off and then, amid the darkness, see flashes of aggressive gunfire.
What Vietnam does well is use its on-location filming to maximum effect.
(He also scolds a soldier for chastising a young Vietnamese boy as a commie.)
So begins the told-in-reverse saga of Jack and Nick.
And so Jack, protector that he is, decides to enlist himself.
I just need to be there.
Hes my little brother, doc.
He calls Jack his own personal Superman always there to get him out of trouble.
(Familiar, isnt it?)
Jack takes Nick to a bar where the lottery airs on national TV.
The reality registers on Nicks face: Hes going to war.
Jack doesnt accept this, however, suggesting hell take Nick across the border.
And he gets pretty far in executing his plan.
Its my time to save the day now, he writes.
Hes not running to Canada.
I wish I could do that right now.This Is Ustries answering that question with Vietnam.
I do tend to find this characterization a little tired.
When Jack appears in his familys memories, the saintliness functions effectively.
When that filter is lost, however, its less convincing or affecting.
In any case, the show moves more aggressively toward the past as it hurtles toward its conclusion.
Just a matter of time before people realize youre actually Superman, Jack enthuses.
He didnt used to be this way, his mom says.
Jacks grandfather stops by, briefly, revealing himself as a drunk.
Of course, were a long ways from Vietnam now.
But Vietnam, the episode, ends where it began with Jack finally reuniting with his brother abroad.
This time we see Nick in the flesh.
Its a fascinating moment, so many emotions overcoming him (Resentment?
), and theres fear in his eyes as if tragedy is in sight.