Every scene in 1917 is a little masterpiece
It is very characteristic how the introductory scene is one where boys don't say a word to each other, but how eloquent their facial expressions are:
Will listens to Sanders’s “Pick a man, bring your kit” with somewhat distant, gloomy interest; then turns away and closes his eyes, as if: "No, no, it's not me. I'm having a nap, you cannot disturb it, find someone other".
Tom watches him super intently, and we know that Will’s chances to be not included are close to zero: "No, it's you, man, it is decided; you cannot escape it".
Blake is brave brilliant enthusiasm himself, which is very admirable; Sco knows from the beginning what it's going to be, and that his eyes closed don't make him invisible.
Hand stretched — last moment of hesitation — and then this mild, youthful smile: "This is my friend; at least it’s going to be something of an adventure".