Kerlan finds this "passageway" between buildings inside the keep deserted at the moment. There is some rubble and garbage on the ground and against the walls here: a few loose bricks, a couple of ceiling tiles, and a small mound of noisome refuse in the SW corner the exact contents of which Kerlan refuses to speculate.
Once Kerlan places the first ladder and vanishes, Tylara will send her familiar aloft to bring warning if there are any signs that the guards are aware of the wizards' presence. She will move swiftly up the ladder.
Kerlan has placed the ladder and gone through the wall near the NW corner of the keep. The guard who remained awake is in the NE tower. Hmmm, not exactly an ideal arrangement, is it? Let's see if he notices anything right away:
Once Tylara comes over, Kerlan speaks with her. "Tylara, you take that door to the left and I'll take the door to the right." Kerlan moves over to the door on the right, prepared to cast Web if neccesary after opening it.
Moving swiftly, Tylara casts Mage Armor on herself and steps to the door as suggested by Kerlan. He puts her pointed elven ear to the door and listens (1d20+3=6). Hearing nothing she readies her longbow and waits for Kerlan to open his door.
Manny get to the ladder as quick as he can and scurries up. Once at the top he looks about, taking stock of what the others are up to. Quickly deciding his hand crossbow is the right tool for whatever might come up next, he draws the bow and knocks a bolt.