Um, need DM info here.
[OOC: I don't know if the old sphere of sneaking is still in effect (10 minute duration). If so, fine. If not, I don't know how long it will take to get to the house. If more than one minute but less than 10, I can repeat the spell. If less than one minute I will cast "lesser sphere of sneaking" (duration one minute, otherwise identical) to spend only 3 points instead of 4 (gotta conserve those points -- we need to get out of here after we get the book, after all!). That said, Adam goes along with the plan. Whatever the marching order, Adam needs to be in the centre, for obvious reasons.]