In Sheep's Clothing

In Sheep's Clothing is a quest in Fallout 4.

Quick walkthrough
This quest starts when the Sole Survivor reaches level 35 and travels to Diamond City. Mayor McDonough will be seen shooting a security guard and fleeing to his office, where he takes his secretary hostage while Piper chases him.

Detailed walkthrough

 * 1) Chase McDonough to his office. (Optional) Talk to a doctor and bring him to the wounded guard. You can also choose to use a Stimpack to heal him. If Curie is with you, she can be asked to take care of the guard, which she will be happy to do.
 * 2) Break into McDonough's office and confront him with Piper. You can either choose to lockpick the door, which is a novice lock, or you can use the button located underneath the secretary's desk.
 * 3) Decide how to deal with McDonough. Passing a medium difficulty speech test will make him release his hostage. He will then request that the Sole Survivor allow him to leave the city, giving him or her the option to comply, kill him on the spot or make him stand trial, starting a fight.