Warhammer 40,000 lore fans are in overdrive after a single page of a new campaign book teased something that’s never happened before in the setting: the meeting of two loyalist primarchs.

The primarchs are the overpowered, genetically-engineered demigod sons of the Emperor, the leaders of the loyalist Space Marine legions before they were broken up into chapters following the catastrophic civil war known as the Horus Heresy. Warhammer 40,000 as a narrative operated for decades with most of the primarchs either thought dead or lost in the warp.

Today, only two primarchs are confirmed alive and active in the current Warhammer 40,000 setting: Ultramarines boss Roboute Guilliman, who returned to the galaxy during the Gathering Storm event in 2017, and Dark Angels chief Lion El'Jonson, who miraculously popped back into existence as part of the Arks of Omen storyline in early 2023. These were galaxy-shaking plot developments for the Warhammer 40,000 setting, and ever since Lion El'Jonson’s shock return to Warhammer 40,000, fans have wondered when he’d finally bump into his brother, Roboute. Now, it looks like that long-awaited family reunion will take place in the coming months, after a new campaign book teased a meeting of the Emperor’s sons.

Word comes from Warhammer 40,000 lore expert Arbitor Ian, who IGN has partnered with for a number of explainer videos, such as the one above. Arbitor Ian got an early look at 500 Worlds: Titus, a soon to be released Warhammer 40,000 campaign book and narrative expansion that features 80 pages of lore covering the beginning of the Ultramarian Reclamation, and published a new video on its most explosive lore reveal.

To back up briefly, Lieutenant Titus from the Space Marine 2 video game has become one of the most recognizable faces in Warhammer 40,000 following its enormous success. To capitalize on Titus’ newfound fame, Games Workshop promoted him to Captain and made him Master of the Watch, which means he’s in charge of defending the 500 Worlds of Ultramar, the realm of Space Marine poster boys, the Ultramarines. With Roboute Guilliman off gallivanting with his Indomitus Crusade, Titus is now in charge of keeping things safe and sound back home, where new Necron threats have emerged, as they always do.

According to the new video from Arbitor Ian, 500 Worlds: Titus has a crucial piece of new lore, found right at the back of the book, that teases a meeting between Guilliman and Lion El'Jonson. It is an intergalactic message written by Lion El'Jonson and intended for Roboute Guilliman that reads: “Brother. We need to talk.”