You make a plan to brush the bubbles aside with your cloak.

You wrap your cloak around your arm for protection and you carefully wave away the bubbles hanging in the air. After a few sweeping motions you create enough of a breeze to slowly move them aside, giving you enough room to pass through them. You keep working your way down the hall like this, choosing which bubbles to displace and which to avoid. Pretty soon you've made your way down half of the hallway and are approaching the door outside.

From here, you can tell that the door outside does lead to the tower - in fact, there is a ladder propped against the tower wall. You could probably make your way to the balcony from there, giving yourself a strategic advantage. You would have to deal with the bubbles around the door however; they are crowded very close together, so it won't be as easy to wave them away. You could also try to dispel them... but on the other hand, it might be better not to change tactics and keep heading for the stairs.