“In a post-apocalyptic future, when a reckless government agent learns that his long lost brother is a test subject in a brutal military experiment, he helps a terrorist cell fight through a dangerous wasteland to free a host of captured children.” (42 words)

This sounds rather interesting!

Just a couple of logic sort of questions that popped for me when I read it. Is the “long lost brother” a “captured child?” The two seem unlikely. If he’s been lost that long, he wouldn’t still be a child, would he? In that same vein, a “government agent” would be of a certain minimum age, so, for his brother to be a “child,” there’s some huge time gap in there. I suspect the brother is now an adult who was part of this experiment as a child? If that’s the case, it just needs a bit more clarity. The “next host of captured children” or something similar would do it.

My other logic question is are there “government” agents and a standing “military” in a “post-apocalyptic” world? There may be, of course, it just made me mentally stop and ask, when I should have been engrossed in the rest of the sentence.

I think you can shorten this a bit without losing much of the drive of the story.

When a reckless government agent discovers his brother was subjected to brutal military experiments as a child, he switches sides to help a terrorist cell rescue the next host of captured children. (32 words)

The post-apocalyptic and wasteland references certainly do give atmosphere, but, they make for a long logline. They’re sort of the same thing too, so, if you want to keep that sense of where/when, maybe just one or the other?

If you want to chop it even more, you could probably even try:

On discovering his brother was subjected to brutal military experiments, a government agent risks everything to rescue the next host of captured children. (23 words)

I do like the twist of him changing up sides though, so, might be worth finding a short version that keeps that element. And, yup, “everything” is sort of bland, but, I think you do need stakes of some kind, so maybe something like “his career – and life!” or similar?

Intriguing idea!

Interesting. Interesting with the old footage inclusion as well, but, have to say, I didn’t get that from the logline itself. I’m sure you’ll sort that part in a minute.

On the logline though, the missing thing for me is the rationale and the stakes.

You think your neighbour is doing something weird, you call the cops? Or, you run downstairs, have a peek, confirm its a body, and then call the cops – if you’re a braver dude. So far, he has no personal interest I can see and is doing something weird instead of doing the usual, but for no particular reason yet?

Does he think he’s in line for the chute? Is there a reason not to call the cops? Does he call the cops all the time because he’s paranoid, and that’s why they do nothing?

“On moving into a new apartment, a perennially-paranoid writer is installing his security cameras when he thinks he’s captured a neighbour dumping bodies – but, unfortunately he’s cried wolf before and the only person paying attention now is the killer.”

It’s way long, and may not fit your scenario at all, but, I think it’s important that we see some rationale for not doing what everyone else would do, and some stakes.