Another game has fallen victim to one of the leakiest E3 seasons ever recorded. According to reliable industry insider Nibel, Ubisoft will announce Rainbow Six Quarantine, a new co-op focused Siege spin-off game, at its E3 2019 conference.

Rumblings of a new co-op shooter from Ubisoft began earlier this week when Kotaku's Jason Schreier suggested on the Kotaku Splitscreen podcast that it would be based on Ubi's scrapped Pioneer project. Industry analyst ZhugeEx partially refuted this claim on a ResetEra thread, saying that the game is indeed real, but it isn't based on Pioneer.

Now framed as a new Rainbow Six game, the pieces are all starting to make more sense. It's likely that Quarantine is based on the popular Outbreak mode introduced to Rainbow Six Siege in March 2018. Combining Siege's tight gunplay and destruction model with the structure of Left 4 Dead, the mode was adored by players. The 3-mission campaign felt surprisingly robust. At the time, players assumed that Ubi would revisit the concept and add more missions, similar to Overwatch's annual PvE events.

Since the event came and went last year, fans have continually pleaded to Ubisoft to bring Outbreak back. And on every occasion, Ubisoft has steadfastly (and frustratingly) insisted that, while a successful experiment, Outbreak was a one-time thing. If Quarantine's existence is to be believed, we now know why: Outbreak is expanding into its own game.

To be clear, we don't know to what degree Quarantine is based on Siege. While the Outbreak mode starred a handful of Siege's operators sent to put down a zombie alien infestation, Quarantine could ditch all of that in favor of its own world and characters. Though, the names "Outbreak" and "Quarantine" do suggest similar themes.

But why make a whole new game instead of slotting it into Siege, a game with a built-in player base? The obvious answer is that Ubi would like to sell you a new game at full price, but it also strikes me as an image issue. In the landscape of competitive service games, products benefit from having a very clear identity.

Overwatch dabbles in PvE here and there, but Blizzard keeps these events time-limited because it ultimately wants players to think of the game as a competitive PvP shooter. In fact, another Schreier report suggests that Blizzard is expanding its PvE ideas into a new, separate Overwatch game. It all feels a bit serendipitous, but Quarantine is likely a similar move for Ubi—a potential spiritual successor to Outbreak quite literally "quarantined" to its own game that doesn't interfere with Siege's competitive PvP focus.

If Rainbow Six Quarantine is legit, we'll hear more about it at Ubisoft's E3 conference on Monday, June 10. To be sure you're there to see it live, here's how to watch Ubisoft's E3 2019 press conference.

Thanks, Eurogamer.