Mission Letter from Delilah is a written note found in Dishonored 2.
Take Heather and Kai. Travel to Karnaca tonight. The others there will give you a roof to sleep beneath and they will keep you out of sight. Watch for our friend from Dunwall.
When the moment comes, strike. If you succeed, I promise you will be rewarded. And beyond that I'll make you a portrait.
- Your Empress Forever, Delilah
The note can be found on one of the three witches around Aventa Station near the end of the mission The Clockwork Mansion.