One of Showtime’s most intriguing series is Billions, starring Damien Lewis and Paul Giamatti as, respectively, Robert “Bobby” Axelrod, billionaire manager of the Axe Capital hedge fund; and Charles “Chuck” Rhoades, Jr., U.S. Attorney for the Southern District of New York. The first three seasons had the two of them at odds with each other, while the fourth saw them working together to try and bring down a common enemy — until the season finale, which indicated they were going back to their separate corners before taking each other on again.

In an interview with Vulture, series Brian Koppelman offered up an explanation for turning them into adversaries again. “It goes to who these characters are,” he said, “and what drives them. We start by asking ourselves questions; usually, we lead from a place of curiosity, so it’s not like there was a strategy. We knew at some point they would be turned toward one another again, but as we were writing the season, it just became clear to us that these two alphas, in the way that they’re alphas, how would they really coexist when each needs to make the world in exactly the form and shape that they see it to serve their own need? How are two people like that going to just coexist peacefully? It doesn’t seem that they ultimately, long term, could.”

Here’s what Showtime says about season five of Billions: “Bobby Axelrod and Chuck Rhoades see their vicious rivalry reignited, while new enemies rise and take aim. Social impact pioneer Mike Prince (Carey Stoll) poses a true threat to Axe’s dominance, and Chuck feuds with a formidable district attorney (Roma Maffia). Taylor Mason (Asia Kate Dillon) is forced back to Axe Capital, where Taylor must fight to protect their employees and their assets. Wendy Rhoades (Maggie Siff) reevaluates her loyalties and forges surprising new alliances that put her at odds with both Chuck and Axe. Julianna Margulies will play Catherine Brant, an Ivy League sociology professor and bestselling author. The series also stars David Costabile, Condola Rashad, Kelly AuCoin and Jeffrey DeMunn.”

Look for the Season 5 premiere of Billions on May 3.