Xarrah would bend down, retrieving the key and holding it in her hand as the couple headed out the north door. Exiting would immediately leave them with three options. To go left on a winding path, to go right on the winding path, or to go straight a bit.
Anh Sang would send off her message, and then retrace her steps. She'd find the marker easily, before heading south. Immediately she'd be forced to turn right, passing one divider before having to make a choice. Heading straight would lead to a dead end almost immediately, while to the left was more options... and a door.