It’s been exactly one year since Ubisoft revealed Rainbow Six Siege, which ended up being our favorite game from last June’s E3. At the outset, Ubisoft’s recipe for reviving the classic FPS series was promising: a five-on-five structure, asymmetrical hostage rescue on compact maps, short matches, and high-fidelity destructibility.

Over the chances we've had to play Siege since then, however, including a full-blown alpha test in April, there's been a void of information about what else Siege contains. Beyond the meager two maps and one mode Ubisoft have shown for the past year, Siege’s scope has been unclear.

At E3 this week, Ubisoft gave an answer to that question. Terrorist Hunt, the franchise's classic PvE mode, is a part of Siege. It's playable solo or with a co-op squad of up to five—and from what I've played, you'll need every member of that squad to handle the AI on Realism, the hardest difficulty setting.

I recorded several matches of Rainbow Six Siege's Terrorist Hunt and split them up across two videos. The first video, embedded directly below, contains three matches on Realism difficulty, played with different class loadouts. Or, I should say, partial matches: we got our asses kicked. The second video is a complete (victorious!) match on normal mode; that one's embedded at the bottom of the article.

The new Terrorist Hunt mode shares much with Rainbow Six Siege's competitive multiplayer: the same classes, maps, and attack-and-defend objectives. In a short presentation before we got to play Siege, Ubisoft talked big game about its AI opponents. The AI can play both sides of the objective modes, either breaching a building on the offensive or defending against your own assault. The AI is smart enough to flank you and can also use the same gadgets and abilities available to players, like setting explosive traps and breaching walls to create new entry points.

Terrorist Hunt includes a few different objectives types: hostage rescue, bomb defusal, and terrorist hunt classic, aka kill 'em all. I only got to play bomb defusal, which sent me and four squadmates into a consulate building to plant defusal kits at two bomb sites. From what I played, getting to those bomb sites was fairly easy, as the map was lightly populated with AI terrorists. Still, any one of those terrorists can be lethal to a sloppy player on realism difficulty. In one round, I got a little gung-ho with a shotgun, jumped over a barricade, and was suddenly bleeding out after taking a couple hits. Then I got flashbanged and blown up with a grenade. That was a short round.

Terrorist Hunt becomes far more difficult once you reach an objective. On bomb defusal, we'd place a defusing device on the bomb site and then spend a fragile minute defending against the AI terrorists. Even with a full squad, this was dicey, as the AI would attack in threes and fours at multiple entry points. They breached windows and walls at every single bomb site I defended, and if we survived the onslaught, it was usually with a couple players dead and the rest injured.

It's going to take an experienced, coordinated team to handle realism, the hardest difficulty mode. Normal mode, which is just one down from realism, seemed too easy by comparison. We played only a single match (our first) on normal, and cleared it easily. That was with one developer, who obviously knew the game well, and four inexperienced players. If we could clear normal on our first try without much difficulty, it'll be up to realism mode to give Terrorist Hunt longevity. Ubisoft talked about randomly selecting a combination of objective types and maps to keep the mode fresh, but I'd love to see some deeper customization beyond that, like tweaking AI behavior and loadouts, time allotment, and the number of enemies.

On first play, though, Terrorist Hunt was a blast. It was tense as I crept through empty hallways, looking for the next enemy around the corner. It was just as satisfying to protect a teammate with my riot shield or breach a window with a hammer as it would be against human opponents. Compared to co-op "Horde mode" shooters, Siege co-op matches are short at under 10 minutes. I can see tackling them again and again with a squad of buddies. Whether that'd be for five hours of 50 depends on how well Ubisoft's AI and hardest difficulty setting hold up to repeat play.