I’m glad you gave a little explanation of the title of this; I read Dulce et Decorum Est in high school, but I didn’t connect the title to that until you said it. And, I love the connection, because that poem is really so great, and I was intrigued to see how you were inspired by it.
As an idea, I love this story. I’ve never considered before what some young wizards did when it came to joining up for the war; many of them probably did not think twice about it, but those who came from Muggle families, such as our Toby here, must have at least given it some thought. That Toby actually decides to join the effort says a lot about his character. That was a nice bit of characterization; he feels so strong a sense of loyalty and responsibility to his Muggle roots that he chooses to leave the protection of the magical world. Toby is a completely new character to the reader, but he is still extremely present in the story. I have a real sense of him, which means that your job as the author was accomplished.
Technically, this story falls a little short of great. There are some small grammatical errors that could have been caught with a more thorough looking-over; I won’t list all of them, but you should just note that everything wasn’t quite perfect with this. A technically clean fic is always more enjoyable to read. One thing is particular that I noticed was your use of ellipses. You have the three periods separated fully from each other (i.e., . . .) when a true ellipse condenses these periods together (i.e., …). It isn’t anything huge, but it does help make the fic look more professional.
The scene between Toby and his mother is something that I wish had been longer. There’s so much emotion to be conveyed there, and I don’t feel like you really got everything out of that that you could have. You told us that Toby’s mother is a witch and his father was a Muggle; more exploration of how Toby’s mother felt about her magical son joining the Muggle army might have been nice. For example, this sentence: Fiercely, she hugged him, as though he were being dragged away. It’s a nice sentence as it is, but I think you could have packed so much more into that moment. The idea of Toby’s mother hugging him as that he is being dragged away is great, but I feel like you could have conveyed that without saying it so obviously. Just the fact that she’s hugging him so tightly or for such a long time, or something in the way she says his name, etc. There’s so much to be conveyed here, and I don’t think you quite conveyed all of it. The scene itself feels a little rushed.
The last section of this is great. I love the description; it fits right in with what I’ve read in WWI literature and seen in movies on the subject. The shift from the battlefield to the Toby’s Hogwarts days is wonderful, too. It’s extremely sad, but it’s also very poignant and well done. Above the screaming of the young soldier and the sound of murderous machinery, Collier thought he could hear Professor Beech droning on about the calming properties of Mandical ferns. I absolutely love that sentence. You handled the shift so nicely; it isn’t jarring at all. I can actually picture this really well as a scene in a movie. And finally, Toby’s death. It saddens me, of course, that he does die at the end of this, but I also kind of figured that he would. The only thing I don’t love about the last sentence is the use of verb ‘impacted.’ For one thing, you used it earlier in this section as well, and it sounded a little repetitive in my mind when I read it. But mostly I just don’t think it’s used correctly. Something doesn’t usually ‘impact with’ something else, or at least I haven’t seen it used that way very often. It just sounds kind of strange in my head. But other than that, the ending of this is great.
Overall, I thought you did a pretty good job with this. There were aspects that I thought could be improved, but I did enjoy this little fic. Keep it up!