Alex's first instinct is to insist that she won't need help. She's pretty sure this is a do or die situation - if she gets in trouble, she's probably dead. But if Evie's serious, and if she's really not going to betray Alex once they get there, having backup might not go amiss.

It's been a long time since Alex worked with another person. She nods curtly, frowning. "Yeah. I can whistle."

She stuffs the map back into the bag and adjusts the strap to sit more comfortably on her shoulder, giving her a little more freedom of motion.

"Come on." No point in putting it off. In about twenty minutes, the guard will change, then it'll be do or die time.