In the 5th mission, Clean House, it’s time to track down some clues. The story moves to London and a house in Camden, where the objectives are to sneak in and clear the house floor by floor.
In the first part of the mission, you have to use the ladder to get into the house and follow Captain Price into the front room and take out the threat there. As you make your way through the house be wary of enemies shooting through doors as you examine them.
Work your way through the house clearing the floors of enemies as you go. When you get to the top of the house be careful as the woman lunges for a detonator at the end, take her down before she gets to it.
At this point, you’ve found a boatload of clues as to the enemies next plans.