Find the Captain of the Akka guard. Ask captain message. Ask captain isa.
Find the secret passage. You will need sustained breath (Under the fountain in Akka, or beneath the pool near the wanton women)
Go to the room with the weeds, and get all weeds. Take the pouches you get from the weeds to the captain.
He will ask you if the messenger died in an accident or you killed him. Ask captain accident.
He will give you a pouch to take to Salah. Go to salah and give him the pouch.
He will praise you on Info.
There might be another ending where you take the message pouch to Richard, but I am uncertain if it works, or what happens. Please update if you know - Giving the pouch to Richard results in nothing. Not even a 'Thank you.'