The "Celtic" Building is a high-rise apartment building in Seattle, Washington that is the base of operations of the terrorist organization Heaven Smile, and the setting of Target00: Angel in killer7. Garcian Smith, after being informed of Heaven Smile's presence in the building by Christopher Mills, heads there to eliminate them. Dan Smith is warned of the dangers by a member of the Red Gunners,a gang that previously operated out of the building, but the gangster is killed by Dan after he transforms into a Heaven Smile (enemy). As the setting of the first mission of the game, the "Celtic" Building serves as a tutorial for the Smith Syndicate's various unique mechanics, as well as introducing the Remnant Psyches Iwazaru, Travis Bell, Kikazaru, Mizaru, Yoon-Hyun, and Susie Sumner.
The Smiths encounter the Angel, who scolds them for eliminating the organization's "children". Harman Smith, unimpressed, shoots the Angel's wings with his rifle, thus leaving her open to defeat by the rest of the Smiths and revealing her to be an avatar of Kun Lan. At the end of the scenario, Harman breaks through the illusion of the Angel and approaches her creator in a confrontation, firing at Kun's God Hand. However, this proves to be ineffective as Kun Lan merely uses the bullet's momentum to fly backwards to the top of the nearby Space Needle.