"Coquilles" is the fifth episode of the first season of the psychological thriller–horror series Hannibal. The episode was written by supervising producer Scott Nimerfro and series creator Bryan Fuller from a story by Nimerfro, and directed by Guillermo Navarro. It was first broadcast on April 25, 2013, on NBC. Although it was the sixth episode produced for the season, it was the fifth in scheduled order.

The series is based on characters and elements appearing in Thomas Harris' novels Red Dragon and Hannibal, with focus on the relationship between FBI special investigator Will Graham (Hugh Dancy) and Dr. Hannibal Lecter (Mads Mikkelsen), a forensic psychiatrist destined to become Graham's most cunning enemy. The episode revolves around BAU pursuing a serial killer that flays his victims and makes them appear as angels. Meanwhile, Graham starts to feel like he is losing grip of his skill and seeks Lecter's help, who tries to cause a wedge between him and Crawford. Lecter also tends to Crawford's wife, who is hiding a secret from him.

According to Nielsen Media Research, the episode was seen by an estimated 2.40 million household viewers and gained a 1.0/3 ratings share among adults aged 18–49. The episode received mostly positive reviews from critics, who praised Dancy's performance as well as the development for Lecter, Crawford and Bella. Some critics, however, expressed concerns about feeling left out of important material due to the omission of the previous episode's airing.

Two police officers find Graham (Hugh Dancy) sleepwalking in the middle of the road and drive him back home. The next day, he visits Lecter (Mads Mikkelsen), who deems it a sign of post-traumatic stress disorder due to the gruesome cases he has been working on, with Lecter blaming Crawford (Laurence Fishburne).

In Trenton, New Jersey, Graham and Crawford arrive at a motel room for a new case. A murdered couple has been found, posed in praying positions with the flesh of their backs opened and strung to the ceiling to give them the appearance of wings. Graham uses his skill to try to understand the killer's intentions, while the BAU Team investigates the room, as the killer slept in front of the corpses and then threw up nearby. At the lab, the team discovers several medications often used together to treat cancer, specifically brain tumors. Graham surmises the killer is transforming his victims into guardian angels to watch over him because he is afraid of dying in his sleep. He confides in Lecter that the pressure of looking into killers' minds is starting to break his psyche and Lecter attempts to use this to create a wedge between Graham and Crawford.

Crawford's wife, Bella (Gina Torres), attends a session with Lecter. She explains some of her insecurities, and it is hinted that she is hiding something from Crawford but does not want to talk to Crawford as he is too busy to worry for her. At her house, Crawford tries to get her to talk, feeling that she has been distancing herself from him, but she does not reveal anything. The killer (Seann Gallagher), who constantly sees people's heads engulfed in fire, kills a man and hangs his body, his flesh once again displayed to look like wings. The BAU Team finds that the killer castrated himself, with Graham concluding that he may try to become an angel himself as angels have no genitalia. He then gets into an argument with Crawford, as Lecter's influence is starting to take over him.

Jimmy Price (Scott Thompson) informs Graham and Katz (Hettienne Park) that the murdered couple were wanted criminals. Graham deduces that the killer thinks he's doing God's work even if he doesn't fully know the person he will kill. At another session with Lecter, it is revealed that Bella has terminal lung cancer and, besides not wanting to having him worried, she wants to soften the pain when she dies. Lecter later tends to Graham, whose sleepwalking continues. During the session, Lecter smells Graham, but he notices this and is taken aback by the action.

The BAU identifies Elliot Budish as the killer and question his ex-wife Emma (Cynthia Preston), who confesses that she left him after he was diagnosed with cancer. She also reveals that Elliot suffocated as a child during a fire and was resuscitated by a firefighter, which sparked Elliot's obsession with guardian angels. She directs them to the farm of the incident but they find that Budish has already died by suicide and transformed himself into an angel. The failure to catch the killer heavily impacts Graham, who questions his skills, but Crawford reaffirms he is effective and says he can quit if he wants. The events of the investigation make Crawford realize the reason for his wife's distant behavior and promises to help her through her illness. The next day, Graham visits Crawford's office, stating that he will continue working with him.