A lot of news came out of Comic-Con last week, but probably none bigger than the reveal that Michael Burnham, the main character on Star Trek: Discovery, was raised on Vulcan by Sarek and Amanda.

Wait–what? Spock has a sister?

All of us who know our Star Trek canon were surprised by the news that Spock has a sibling we’ve never heard about before. Michael Burnham, it turns out, was adopted by Sarek and Amanda after her parents were killed, and that makes her Spock’s sister. (And she’s not his not half sister or stepsister as various websites claimed; an adopted sister is a sister.)

Some unhappy voices rose in the Trek community. What? That’s not possible! We would have known! But I disagree. I think it’s entirely plausible that Spock could’ve had a human sister he never mentioned, and it doesn’t violate canon or challenge anything we’ve ever known about him before. I’m going to explain why.

Spock never mentioned his brother Sybok, either

Okay, let’s get Sybok out of the way first. (He’s not my whole argument by any means, so stick around.) In Star Trek V: The Final Frontier—hardly a fan favorite, but it does have some fun moments—we meet Spock’s half brother, son of Sarek, whom we’ve never heard of before. Kirk is shocked, especially when Spock explains that they were raised together, as brothers. “Sybok couldn’t possibly be your brother because I happen to know for a fact that you don’t have a brother,” Kirk says. He’s sure of it. When Spock explains the situation, Kirk—who let’s not forget, sees Spock as a brother to him—is shocked that he never knew about it, and McCoy says, tellingly, “Spock, you never cease to amaze me.”

Spock: “I was not disposed to discuss matters of a personal nature.”

Spock also didn’t reveal who his parents were

Let’s go further back, to The Original Series, season two, and “Journey to Babel.” The Vulcan ambassador and his wife come aboard, and Kirk asks Spock if he wants to beam down to Vulcan while they’re there to see his parents. “Captain,” Spock tells him, “Ambassador Sarek and his wife are my parents.” Kirk, who risked his career to bring Spock to Vulcan for pon farr and then his life to save him from a battle to the death with Stonn (“Amok Time”), had no idea, because Spock never mentioned it. He also never told anyone he was engaged to T’Pring until she was staring them all in the face on the Enterprise viewscreen.

Kirk and McCoy had witnessed one of Vulcan’s most sacred, private rituals, and still didn’t know that Spock’s parents were the representatives from Vulcan coming aboard the Enterprise until they were standing right in front of them.

More secret siblings in Star Trek

Spock’s not the only character in Star Trek history to be reticent when it comes to family. I dug into my own memory banks to see who else was guilty of the same omission, and just how much we knew about our crew members’ families in the first place.

Chekov, once manipulated into inventing a fictional murdered brother in “Day of the Dove,” was an only child, and there were others: Will Riker, Deanna Troi (whose sister Kestra died shortly after Deanna’s birth), Julian Bashir, B’Elanna Torres, and Harry Kim.

But Kirk had a brother; he first mentioned him in “What Are Little Girls Made Of?,” significantly NOT to share information with his crew mates but to test the knowledge of his android duplicate. His brother died on Deneva later that season (“Operation: Annihilate”), and Kirk’s nephew survived, but was never mentioned again.

Scotty never talked about his family, but in Star Trek II: The Wrath of Khan, we found out that he had a sister. Actually, we found out in the novel, as the scenes were cut from the movie (and then later restored), but Peter Preston, who died in the line of duty, was Scotty’s nephew. “My sister’s youngest,” he told Kirk. I don’t recall the canon police shouting that we’d never heard Scotty had a sister before.

The Next Generation – Ishara, Robert, and Nikolai

Moving on to The Next Generation, “Legacy” introduced us to Tasha Yar’s sister Ishara. Ishara is hardly shocked that her existence never came up, but Data is. “It is surprising to me,” he tells her. “Tasha and I spent much time together. We had a considerable number of conversations.”

After Picard’s ordeal with the Borg, he took advantage of the Enterprise’s stop on Earth to go back to the village where he grew up, and he visited his previously unheard-of brother Robert (“Family”). Even when he’s telling Troi that he wants to walk the streets of his home village, he doesn’t say a word about visiting his brother.

Early in season one (“Heart of Glory”), Worf talked about a foster brother to some fugitive Klingons, and six seasons later, Nikolai finally turned up (“Homeward”), with never a mention between. (And he was Paul Sorvino!)

Quick takes: Spock wasn’t the only one who didn’t talk about siblings

A little digging unearthed some more examples.

O’Brien had brothers, and only ever said so to Quark, because he was directly asked (“Invasive Procedures”)

Kira spoke of her brothers only to Bareil, as they were becoming more intimate (“Shadowplay”)

While Trip Tucker’s crewmates all knew that his sister was killed by a Xindi attack (“The Expanse”), the only person he ever talked to about his brother was a Vulcan engineer (“Fusion’)

Chakotay and Janeway each mentioned having a sister when Voyager finally got back in contact with Earth, in Voyager‘s final season (“Author, Author”), but neither one had ever brought them up before

It seems quite natural that the crew wouldn’t discuss their families much once they’re serving aboard starships and space stations. Even in today’s workplace, a lot of people aren’t big blabbers about their personal lives. Like Neelix (who frequently talked about his sister Alixia), I talk about my siblings all the time, but not everybody else does, and it doesn’t seem strange. To each their own.

The timeline: Spock and Michael’s upbringing

Spock was born in 2230. In 2250, he joined Starfleet, and thus began the 18 years of silence between him and Sarek. In 2254, he began serving under Captain Pike on the Enterprise.

Kirk took command around 2265, so that sets Discovery, known to be set 10 years before Kirk takes command of the Enterprise, in 2255. Spock would have been 25 years old, and Michael Burnham? We don’t have an age for her yet, but Sonequa Martin-Green, who plays her, is 32. If Spock and Amanda raised her after her parents died, which is part of her back story, then she and Spock were raised together, likely with Sybok as well.

The fly in the ointment: “Yesteryear”

Now here’s where I get stuck. In The Animated Series‘ “Yesteryear,” Spock visits himself as a child, and Michael and Sybok are nowhere to be seen. That leaves two options: either it was both before Sybok and Michael moved in, or they were both away, perhaps at friend’s house, and Spock wasn’t invited. He was a loner, remember?

Sarek wasn’t the easiest dad

What’s especially fascinating, The Animated Series‘ wrench in the works aside, is that these three kids raised together turned out to be so different. Sybok rebelled against traditional Vulcan logic, embraced emotion, and was eventually banished. Spock incurred his father’s disapproval when he gave up the opportunity to go to the Vulcan Science Academy and headed for Starfleet instead. Michael is a human raised with Vulcan traditions and Vulcan control, but seems to have Sarek’s support for her Starfleet career, since we know that he encouraged Captain Georgiou to be her mentor. Sarek clearly had different expectations for his half-Vulcan son than for his fully human daughter, especially after the disappointment of Sybok; can you blame Spock for not wanting to talk about it? His choice to enter Starfleet led to an 18-year silence, while his sister was actively encouraged to join. She was the only human to attend the Vulcan Science Academy, while Spock rejected it, giving his father even more of a reason to guide Michael as he shunned Spock.

Yes, Michael Burnham is Spock’s sister

The idea of a human raised by Sarek and Amanda–who seems to have a stronger connection to her Vulcan father than to her human mother, from what we know so far–is a fascinating one, and will clearly have a big impact on Burnham’s decisions and relationships, and might lead to some great stories. Remember, Spock didn’t tell his crewmates about his parents or his “brother” Kirk about his half brother Sybok, and is known for being an incredibly private person, so is it really a shock that he wouldn’t have mentioned Burnham before?

Not to this fan.

Special thanks to the smart people at Memory Alpha, who make it possible to verify and back up all the info in my Star Trek memory banks!

Star Trek: Discovery premieres on September 24th on CBS with all subsequent episodes on CBS All Access in the US. In Canada Star Trek: Discovery will premiere on Bell Media’s CTV and the Space Channel on the same night. Netflix will launch Star Trek: Discovery on Monday, September 25 to countries outside of the U.S. and Canada.

Keep up with all the Star Trek: Discovery news at TrekMovie.