Read this excerpt from little brother and answer the following questions in complete sentences using proper grammar and punctuation:

marcus manages to flag down a vehicle and they get more than they bargained for…

it was a military-looking jeep, like an armored hummer, only it didn't have any military insignia on it. the car skidded to a stop just in front of me, and i jumped back and lost my balance and ended up on the road. i felt the doors open near me, and then saw a confusion of booted feet moving close by. i looked up and saw a bunch of military-looking guys in coveralls, holding big, bulky rifles and wearing hooded gas masks with tinted face-plates.

i barely had time to register them before those rifles were pointed at me. i'd never looked down the barrel of a gun before, but everything you've heard about the experience is true. you freeze where you are, time stops, and your heart thunders in your ears. i opened my mouth, then shut it, then, very slowly, i held my hands up in front of me.

the faceless, eyeless armed man above me kept his gun very level. i didn't even breathe. van was screaming something and jolu was shouting and i looked at them for a second and that was when someone put a coarse sack over my head and cinched it tight around my windpipe, so quick and so fiercely i barely had time to gasp before it was locked on me. i was pushed roughly but dispassionately onto my stomach and something went twice around my wrists and then tightened up as well, feeling like baling wire and biting cruelly. i cried out and my own voice was muffled by the hood.

i was in total darkness now and i strained my ears to hear what was going on with my friends. i heard them shouting through the muffling canvas of the bag, and then i was being impersonally hauled to my feet by my wrists, my arms wrenched up behind my back, my shoulders screaming.

i stumbled some, then a hand pushed my head down and i was inside the hummer. more bodies were roughly shoved in beside me.

"guys? " i shouted, and earned a hard thump on my head for my trouble. i heard jolu respond, then felt the thump he was dealt, too. my head rang like a gong.

"hey," i said to the soldiers. "hey, listen! we're just high school students. i wanted to flag you down because my friend was bleeding. someone stabbed him." i had no idea how much of this was making it through the muffling bag. i kept talking. "listen—this is some kind of misunderstanding. we've got to get my friend to a hospital—"

someone went upside my head again. it felt like they used a baton or something—it was harder than anyone had ever hit me in the head before. my eyes swam and watered and i literally couldn't breathe through the pain. a moment later, i caught my breath, but i didn't say anything. i'd learned my lesson.

in three to five sentences, summarize the conflict marcus is facing in this excerpt.