Over the course of its five seasons, Chicago P.D. has seen its fair share of guest stars come and go — many of them crossing over from Chicago Fire and Chicago Med. With the Dick Wolf drama approaching its 100th episode, we're celebrating the major milestone by taking a closer look at some of the bigger names that have dropped by. Here are nine stars you forgot appeared on Chicago P.D.

Charisma Carpenter

The Buffy the Vampire Slayer and Angel star dropped by P.D. for two episodes during the show's third season as Brianna, the owner of a dispensary that gets robbed by a local gang. Working closely with Jay Halstead (Jesse Lee Soffer), it looked like they'd become more than just friends — she even asked him out to dinner — but a grueling investigation and Jay's lingering feelings for Lindsay put a stop to their potential romance.

Stella Maeve

Before she was a series regular on The Magicians, Maeve appeared in the first two seasons of the Dick Wolf drama as Nadia, a former prostitute who Lindsay (Sophia Bush) helps get clean. Landing a job as an administrative assistant in the Intelligence Unit, it took a while for the crew to warm up to her but she eventually earned their acceptance. Unfortunately, Nadia was murdered by a serial killer towards the end of Season 2 and her death sent Lindsay into a downward spiral.

Chris Redd

Hailing from Chicago, it makes perfect sense that the current Saturday Night Live cast member would have appeared on a show based in his hometown. Redd stopped by in Season 1's "Thirty Balloons," which centered around Atwater (LaRoyce Hawkins) and Burgess (Marina Squerciati) struggling to keep their new patrol car in mint condition. The comedian appears as a supporting character name Carl.

Bianca Lawson

The star of such shows as Teen Wolf, The Vampire Diaries and Pretty Little Liars, Lawson played the girlfriend of a drug trafficker during P.D.'s second season. When her character suddenly disappears in "We Don't Work Together Anymore," Intelligence suspects she might be helping her boyfriend until they realize she's been kidnapped. Thankfully, the team finds her just in time and she walks away unscathed. Whew!

Jack Coleman

In addition to starring in shows like Heroes and Castle, Coleman also played Caroline's (Candice King) dad Bill Forbes on The Vampire Diaries and brings those fatherly qualities to P.D. in Season 2 as Ruzek's (Patrick John Flueger) dad, Disco Bob. The episode not only gave us more insight into Ruzek's background but also revealed that Bob took a safer beat in order to be present in his son's life. The episode gets bonus points for also featuring Supernatural's Mark Pellegrino in a guest role.

Storm Reid

Trudy Platt (Amy Morton) is one tough cookie but she had a soft spot for Reid's character Diane in Season 2's "Get Back to Even." Platt ends up caring for the young girl when her drug-addicted aunt fails to pick her up from the station. Rather than let Diane go back to an unsafe environment, Platt calls in CPS to help find her a new home. Reid, who stole the show during her limited appearance, will next be seen in Ava DuVernay's A Winkle in Time opposite Oprah Winfrey and Reese Witherspoon.

Billy Burke

Though he has starred in shows like Zoo and Major Crimes, Burke is also recognized for playing Bella's (Kristen Stewart) father Charlie Swan in the Twilight saga. In Season 4 of Chicago P.D., he played a famous local baseballer who happened to be an old friend of Olinksy (Elias Koteas). He's investigated by Intelligence when a young girl is found dead in his house. Spoiler alert: He turns out to be the killer but claims it was an accident. Still, the case proved to be too much for Olinksy who turned in his badge at the end of the episode. Don't worry, he eventually gets it back.

Pro Wrestler Colt Cabana

The professional wrestler randomly pops up in Season 4's "Seven Indictments" as a suspect in Intelligence's ongoing investigation into the murder of an unidentified man. Despite being one of the sport's top indie stars, he played a regular old Joe in the episode and did not drop an elbow or deliver a devastating suplex as a result. On the plus side, he was eventually ruled out as the culprit.

Mekhi Phifer

You might recognize him from his starring roles in 8 Mile, ER or Showtime's House of Lies, but did you know the love interest from Brandy and Monica's "The Boy Is Mine" music video also dropped by Chicago P.D. this season? In "Captive," he and Atwater were kidnapped after being accused of stealing cocaine from another dealer. He and the Intelligence officer have their own beef given that Atwater is the one who killed his only son. The two have a much-needed heart-to-heart during their captivity and finally make peace before being rescued.

Chicago P.D. returns Wednesday, Feb. 28 at 10/9c on NBC.

Charisma Carpenter, Jesse Lee Soffer; Chicago P.D.Charisma Carpenter, Jesse Lee Soffer; Chicago P.D.