We already know that Romulans will feature heavily in Star Trek: Picard, based on the current trailers. And if you’ve been reading up on the lore ahead of Picard’s premiere next January, you will have also heard of the Remans, who featured heavily in the plotline for Star Trek Nemesis. That was the last time we saw Sir Patrick Stewart on screen as Captain Picard.

StarTrek.com published a handy guide over the weekend, explaining who the Romulans and Remans are, and why they are inextricably linked. In an excerpt from their book, Star Trek 101: A Practical Guide to Who, What, Where, And Why, Paula M. Block and Terry J. Erdmann explain that Romulus and Remus, the home planets of the Romulans and Remans, are sister planets within the same system. Romulus is a “typical alien world” - habitable - while Remus is hostile, to say the least. According to the StarTrek.com piece, “About the only thing the planet is good for is mining, and for many years the dominant Romulans have forced the Remans to live under brutal conditions and work the mines.” Remans, under the leadership of the Picard clone Shinzon, eventually rose up and assassinated the entire Romulan senate at the start of Star Trek Nemesis.

You can easily tell Remans from Romulans by sight. Romulans count Vulcans as their ancestors, and look it. Remans, on the other hand look decidedly more Nosferatu-like, with “gray skin, cadaverous frames and catlike ears” - a product of their time spent in the mines beneath the surface of Remus.

Star Trek 101: A Practical Guide to Who, What, Where and Why is available in Kindle and paperback formats now. The authors, Paula M. Block and Terry J. Erdmann, are experts in Star Trek, having previously worked in licensing and publicity for the franchise, and having published numerous other non-fiction guides and companions.