Manama is the capital and largest city of Bahrain.
A team formed by Phil Coulson, Melinda May and other agents went to Manama in Bahrain to perform an "Index Asset Evaluation and Intake" mission, in order to evaluate a person gifted with superpowers, adding them to a list meant to monitor and protect them.
During the mission, a civilian girl and some agents were stuck inside a building, being held by the followers or worshipers of the individual they went to evaluate. May took it upon herself to take them out, so she entered the building and crossed off the enemy force, without revealing how she did it.
Because of the mission, May changed from the warm person she used to be to a cold woman, and although Coulson tried to comfort her, she did not reveal to him what actually happened.