The 6th season of Mad Men has had its share of mysteries. Fans have gone wild searching for clues that might help them find out what makes Bob Benson so damn chipper in the face of so much existential angst, or why Megan was purposely put in the same shirt as Manson family victim Sharon Tate. But one secret story-line evaded the internet’s watchful eye… until now.

In episode 8, entitled “The Crash,” the Draper home was invaded by a lady claiming to to be Bobby and Sally Draper’s grandma. While the shrewd Sally Draper knew something was fishy and alerted the authorities, poor, sweet, simple Bobby Draper was only confused. If this lady was black, and she was his grandma, does that make him black? This inner turmoil escaped his mouth in the form of a single line: “Are we negroes?”

But he never got his answer.

Of course you’re black, little Bobby! Now help a sister out and get me your mom’s jewelry.

While the overall issue of this home invader was solved on the show when the police apprehended her, Bobby’s confusion was never addressed. Did someone take the time to explain to him what was going on? Don surely didn’t. He was unconscious. It’s not unreasonable to think that the adults were so distraught they didn’t have the presence of mind to explain every small detail of what was going on to the perpetually bewildered Bobby Draper.

This conflict was subsequently dropped once Sally and Don became the focus of the following episodes and Bobby was off at summer camp, but the conflict still remained. What thoughts could be going through Bobby’s naive little brain while he was at camp, far away from an adult he could confide in? “Do I have to get new friends?” “Are we going to have to move to a different neighborhood?” “Should I get more involved in this whole Civil Rights business?”

Much like several other loose ends throughout the season, the last episode finally addressed Bobby’s dilemma. The final scene shows Don taking his children up to the dilapidated house that he grew up in on the rough side of town.

Sitting on the porch is a small black boy, staring at the family with the same bewilderment that was etched on Bobby’s face since his life crisis in Episode 8.

Don then proudly tells his kids, “This is where I grew up.”

Bobby’s face practically implodes. Look at that kid.  He sees his father’s childhood home, and on the stoop is he could only assume to be a family member. Perhaps a black cousin or secret brother he never met until that day. In his mind, that solidifies it. The revelation is written all over his face. Don–forever the careless dad–has accidentally convinced his son that he is black.

Sally then gives her dad a look that some have considered to be a father-daughter moment of understanding. But look at her face. She’s not thinking “oh how nice, my dad is maybe a little more relatable than I thought!” She is thinking “ugh, dad, why do you have to go and confuse the poor kid like that? This is going to take years to straighten out.”

There is no telling how Bobby’s secret revelation will affect the final season next year. Will he carry this knowledge of his identity with him secretly like his father does? Will Don flip on the TV to see his son at a Civil Rights protest, fighting for the freedoms of his people? Will Bobby invent rap? Only time will tell. Whichever way the writers go, one thing is crystal clear: Bobby definitely thinks he’s black.