Just in case, Same shows his marvelous climbing skills as he did in the well before, and in the unforntunate event that the walls/ropes aren't strong enough to hold Sams weight, Lips stays ready to use a levitation spell.
Which he most likely will use on himself, since Lips isn't very good at climbing. Maybe he can levitate Mouse at the same time, assuming that the kid, too, isn't very eager to try this climbing session.