Kieran Culkin and Macaulay Culkin Matt Winkelmeyer/Getty Images; Amy Sussman/Getty Images

In a sneak preview obtained by Entertainment Weekly on Tuesday, February 20, Dr. Plowp (Kieran) is seen trying to build a relationship with colleague Dr. Sleech (Stephanie Hsu).

Things get tricky, however, when Dr. Plowp’s siblings (Macaulay, Rory, Christian and Shane) enter the picture and become invested in Dr. Sleech’s emotional state.

“Is this a sex dream or a sex nightmare?” Dr. Sleech wonders aloud as she meets Dr. Plowp’s brothers.

“Why not both?” Dr. Plowp responds. “These are my brothers.”

The project will mark the first acting opportunity for all five brothers together. But more than 30 years ago, Kieran, 41, starred alongside his older brother Macaulay in Home Alone<and its subsequent sequel, Home Alone 2: Lost in New York, where he played Kevin McCallister’s cousin Fuller McCallister.

After the role, Kieran went on to star in the Father of the Bride franchise and . Most recently, he received critical success for his role as COO Roman Roy on the HBO series <Succession.

Long before finding fame with his brothers, Kieran remembered a simple childhood being raised in a New York City apartment by his parents.

“It was just a hallway, and there were no separating doors, except for the bathroom, which didn’t have a lock,” he told Vanity Fairin 2018.

“They raised seven kids in that apartment— for years! They just kept bringing babies home to this little space.”

While Kieran has since found success as a Hollywood actor, he learned from brother Macaulay that fame isn’t all glitz and glamour.

In a March 2023 interview with Esquire, Kieran described the discomfort he felt witnessing his brother struggle with overnight fame after appearing in Home Alone.

“Even at that time, as a kid, I remember thinking, ‘That sucks for him,’” he told the publication. “I had this unhealthy relationship with what I did for a living. I really wanted to do it, but I didn’t want to be successful at it.”

The Culkin brothers aren’t the only familiar faces expected to make an appearance on The Second Best Hospital in the Galaxy<. Previously, Prime Video confirmed Tracee Ellis Ross, Bowen Yang and Jay Ellis will have roles in the first season of the animated sci-fi comedy.