What do you think would be a good Dark Brotherhood Mission?

My idea would be the standard sneak into a castle, and assassinate *insert target here* mission. I'm ripping off the Minotaur myth a bit, but you'd have to get through a dark labyrinth with a huge, hideous, and powerful unique monster.

It would be wandering around the labyrinth, and could appear at anytime. You have the option of sneaking to the exit, or confronting the creature(or being confronted by the creature). Also if you were too close to it, even from behind, it would detect you.

Post your ideas please.

This will be hard. I usually destroy them.

A mission where you have to take out multiple targets in one go. They all have to be eliminated differently.

Helping an Elderly old Warlock cross a canyon with Armored Gaint werewolves at the tightrope spanning across the deepest part to help him squash a flying stick of butter.