It's My Birthday, Too is a short story in The Dresden Files series by Jim Butcher. It is set between White Night and Small Favor,. It was originally published in the anthology Many Bloody Returns, and is included in the anthology Side Jobs.
Molly Carpenter and Harry Dresden have just returned from battling slime demons and are cleaning things off. Before driving his apprentice home Harry decides to bring Thomas Raith the birthday gift he's bought for him. Molly admits she knows they are half-brothers.
Thomas is at the Woodfield Mall playing a game of "Evernight" as a favor to Sarah, one of his employees. The mall is closed but one of the shops is lit up, without curtains, and some cars are still in the parking lot. Two individuals in long black hoods walk into the mall; Harry takes out his .44 revolver and goes inside.
Inside the shop a group of people dressed predominantly in black appear to be vampires, but their acne reveals them to be young people in costumes. Security guard Raymond stops him, asking why Harry is around and admitting he recognizes Harry from six or seven years ago at Shoegasm. They're joined by Thomas and Sarah, prompting Raymond to go outside to fix a broken camera.
Calling for Molly to join them, they notice she's in psychic shock after witnessing the killing of Raymond and that something has entered the mall that should not have. The streetlights go out and an attempt to contact Karrin Murphy on the phone fails; electricity goes off. A car crashes into the mall and lights start flickering as if a child were experimenting with the switches. A voice on the public announcement system introduces the presence of Constance Bushnell, who disappeared one year earlier and has returned to exact vengeance on the "Evernight" players.
While Thomas watches over the group of youngsters, Harry enlists help from the Shoegasm cobbs in finding out that Bushnell has become a Black Court vampire and fights back, destroying her and her minions.