When a man wearing wings is found dead on the floor of a Catholic church, Det. Mac Taylor (Gary Sinise) is unfazed. Det. Don Flack (Eddie Cahill) isn't rattled either. After all, their profession involves some uniqueness at times. They suspect an earthly hand rather than a heavenly one.

Dr. Sid Hammerback (Robert Joy) confirms this after finding a miniature video camera upon autopsy. He tells Det. Lindsay Monroe (Anna Belknap) the cause of death was a broken neck. Adam Ross (A.J. Buckley) and Dr. Sheldon Hawkes (Hill Harper) work with Mac to figure out from which rooftop the 'angel' launched himself. By trial and error, death is proven an accident. The victim was attempting to become an Internet star, and miscalculated both harness rope strength and impending velocity. He was dead before hitting the church floor.

Meanwhile, Det. Stella Bonasera (Melina Kanakaredes) has a problem of her own. When Det. Scotty Valens (Danny Pino, Cold Case) arrives from Philadelphia to start an investigation, DNA evidence implicates Stella. However, the extent is unknown. She offers her assistance in any way she can. Det. Danny Messer (Carmine Giovinazzo) provides backup, but even he cannot re-direct the road away from Stella.

The confrontation between her and Valens makes her look guilty. Danny later asks Stella privately what is going on, but she doesn't know. Eventually, one lead takes the cops to a movie theater. Processing shows the primary crime scene is in New York. Once Valens leaves, Stella continues processing the case and ends up at an apartment. When the woman answers, it is someone Stella knew from the time she spent in foster care. This is the killer who wanted revenge for childhood abuse. Although Stella understands, she promises to return the next day to make the arrest.

Mac opened a can of worms after Clay Dobson, a serial killer, died before being arrested. The evidence was clear, but Dobson jumped off a roof rather than let Mac put him in handcuffs. Unfortunately, there is going to be a police investigation. Since the DA decided not to bring charges, Mac figures the department is simply trying to make an example of him.

When he asks the police chief (Mykelti Williamson, Forrest Gump) to drop the case, his request is denied. The comment is made that if Mac followed procedure, he has nothing to worry about. However, the chief does not stop there. He goes on to imply Mac should not consider himself above scrutiny.

I thought this episode was a little convoluted. Did the police chief imply he wants corrupt officers in his department? Surely not. Mac, on the other hand, should realize he lived and Dobson died. Since he was determined to bring Dobson down, an investigation makes sense. Stella did the right thing in the end. She told her 'blood sister' being hurt is no excuse for murder. Flack knows Mac well enough to believe him about Dobson, but he also understands he will have to be truthful with Internal Affairs when they ask.