Indeed - the stone drops (causality) bringing the escaping couple to the attention of the guards... nice. When you storyboard the dropping stone - it might give you an opportunity for some comedy - as, at ground level now, the audience sees it fall on the head of passing guard - cue big reaction shot - heads look up; cut to Princess *gasp*; cut to guards piling into door of tower: back to Princess etc... Anyway, now you should start directing with a pencil and working out all the filmic language that way - text can only show you so much... time to draw!
Agreed! Exciting times! :D