Martin Scorsese’s critically acclaimed 2006 crime thriller, The Departed, won critical acclaim and legions of devoted fans for its twists, turns, and moral ambiguities. Among all the double-triple crossing and executions, one of the subtler threads weaving through the film was the love triangle involving Madolyn, played by Vera Farmiga, who becomes entangled with both Billy Costigan (played by Leonardo DiCaprio) and Colin Sullivan (played by Matt Damon). In a world of fundamental duality, Scorsese leaves the audience with one burning question: who is the real father of Madolyn’s baby?

As the plot unravels, Madolyn is revealed to be pregnant, but we’re never explicitly told which of her two lovers fathered the child. The film plays with ambiguity, letting viewers decide based on subtle hints and thematic elements. Both Costigan and Sullivan are potential fathers – but a closer look at the evidence within the story suggests a likelier candidate. The theme of infertility, especially concerning the more ‘evil’ characters in the film, acts as a significant clue.

Early on, Madolyn confronts Sullivan over his inability to perform sexually. While discussing the prior evening’s events, she remarks, “You know, it’s all right. Guys tend to make a big deal out of it. It’s actually quite common”. This is more than just an offhand mention; Scorsese rarely includes scenes without intent. Later, when she informs Sullivan about her pregnancy (in a rather emotionless way, we might add), the secrecy surrounding the child’s paternity leaves room for speculation.

A compelling argument can be made that Billy Costigan is the more likely father. Let me explain: It’s not only because of the noted sexual issues with Sullivan but also due to a recurring theme of infertility among the antagonistic characters. For instance, Frank Costello’s wife, Gwen, is shown reading ‘Getting Pregnant’, strongly hinting at possible pregnancy issues within their relationship. Could this be her fault? Sure. Is it more likely Frank’s? We think so.

Billy Costigan is likely the father

Further cementing this thematic link is an exchange between Frank and Colin, where Colin pointedly jabs at Frank’s lack of offspring. In a charged conversation, Frank states, “I know you, Colin. You know I’d never give you up. You’re like…” to which Colin furiously interjects, “A son…to you? Is that what it is about, all that murderin’ and fuckin’ and no sons? What are you, shooting blanks?”

This theme of infertility contrasts sharply with the film’s exploration of father-son relationships. The father figure’s shadow looms large over many of the main characters, creating a backdrop against which questions of legacy and lineage play out. Beyond knockout performances and a memorable moment between DiCaprio and Jack Nicholson, in this sprawling inter-generational saga of people straddling both sides of the law, Scorsese consistently underscores the importance of paternal forces and male fragility.

It’s heavily hinted at: Billy Costigan is the real father. But, with his erratic behaviour, psychotic tendencies and self-described mental instability, Madolyn makes the call to raise her baby as Sullivan’s child – he is the more outwardly stable and secure, after all. In the end, though (massive spoilers incoming), both men get unceremoniously shot in the head, leaving Madolyn alone to raise her child. Tragic.