Strap on your combat boots. No amount of basic training could have prepared you for War Machine, the explosive action thriller now streaming only on Netflix.

The logline alone lets you know you’re in for a mission that’s anything but routine: “During the final stage of US Army Ranger selection, an elite team’s training exercise turns into a fight for survival against an unimaginable threat.”

Watch the trailer above for a better look at that “unimaginable threat” and all the havoc it unleashes, and read on for more about the fiery, otherworldly ending of War Machine.

Who’s in the War Machine cast?

The sci-fi action spectacle, directed by Patrick Hughes, stars:

• Alan Ritchson (Reacher) as a soldier known only as 81
• Dennis Quaid as Sheridan
• Stephan James as 7
• Jai Courtney as Squad Leader
• Esai Morales as Torres
• Blake Richardson as 15
• Keiynan Lonsdale as 60
• Daniel Webber as 57

What happens in the War Machine ending?

The “unimaginable threat,” as it turns out, is a killer robot from outer space that’s intent on destroying everything that its lethal beams can reach. Tragically for 81 and his fellow recruits, the machine is highly effective at achieving its goal. The training mission turns into a brutal massacre featuring plenty of gory, heroic deaths. The only survivors are 81 and 7, the latter of whom is badly injured.

Although the machine seems invincible at first — especially since the trainees aren’t armed with lethal weapons — 81 is able to exploit a major weakness. In the final, fiery showdown, 81 clashes with the space robot, bulldozing it against a quarry wall. He activates a conveyor belt that unleashes a cascade of rocks into the machine’s ventilation system. The rocks jam the vent, turning the machine’s murderous energy against itself, resulting in a massive barrage of explosions that does not disappoint.

But there’s no rest for 81, a true man of action. Tens of thousands of machines just like the one he defeated are headed to Earth. While 81 and his recruits were busy fighting to survive, armies around the world mobilized to form “Operation Global Shield.” Sheridan welcomes him as a Ranger, and 81 boards a helicopter to join the global mission.

What is the real name of 81, Alan Ritchson’s character?

Aboard the chopper, as 81 is getting some much-deserved shut-eye, a sergeant shouts, “Anybody catch his name?”

None of his new comrades-in-arms did, so 81’s name will remain a state secret. If that information ever gets declassified, we’ll be the first to let you know.

Stream War Machine now, only on Netflix.