The work of honing and expanding a treatment gets underway. In revisions, I find it good to take your time and really work on individual scenes - especially ones that gives us a greater lens into the chaarcter's mind and psychology. Even in an ostensible old-school-esque adventure yearn involving lost Russian treasure, it's still important to ensure consistent and interesting characters who gain something out of the experience beyond material wealth. In this case, it's a story about ideals and expectations - how we can have something set in our minds, how we get disappointed, and how learn to accept, and possibly even love, the change.
Indeed, it is tempting to throw in loads of trivial details to pad out a treatment - here is where you can be tempted to go really purple prose in your writing. Now, sometimes, there is leeway: if building up a picture of the world or environmnet helps you decode or unravel the character, then that's fine. But exorbitant detail about things like clothing, or over-descriptive actions, or just minor elements of the scene that don't connect to the core dramatic action - ditch them.
Something else that I'd like to highlight - what happens when you don't know everything that a character will do, or how a scene will play out? Is it right or proper to force yourself to slow down to really finetune one element, or do you just move on? Now, you might think it's the former, since I've talked at length how this treatment was going to be a more deliberate affair than past ones. However, I take the cue from C. Robert Cargill on this - if in doubt, just put in a placeholder for what you want to happen in the scene. Remember, when you write on spec, you're on no one's schedule but yours - do what you have to, but getting it right is more important than being a perfectionist.
Next time, onto the step outlines. Let's see what ends up changing.