Call of Duty: Modern Warfare finally pulled the curtain back on its 4-player co-op Spec Ops mode with an action-packed trailer. The very end of the trailer includes a brief scene that shows an undisclosed enemy shooting a fallen soldier, teasing the return of a major Call of Duty villain in the new game. However, Call of Duty: Modern Warfare fans seem to be split on who exactly the teased villain is.

The brief clip obscures the identity of the shooter, and it just so happens that there are multiple Call of Duty villains who have shot people while they're down in a manner similar to what's seen in the clip. Fans have guessed that the shooter is Zakhaev, Makarov, or Al Asad, though there are some that believe the teased Call of Duty: Modern Warfare villain is actually Lieutenant General Shepherd. Shepherd, some may recall, played a role in one of the most shocking Call of Duty moments in history, when he betrayed the United States and killed fan-favorite characters Roach and Ghost in Modern Warfare 2.

It remains to be seen if this villain will play a role in the Call of Duty: Modern Warfare campaign, or if they will be relegated to the Spec Ops mode. The Operations in Spec Ops will have players take out key targets in the Al-Qatala terrorist organization, so it's possible that the character teased here is one such target.

Since Activision and Infinity Ward have gone to some measures to obscure the character's identity, it's unlikely that we will find out who it is before launch. The Call of Duty: Modern Warfare villain is being kept secret for a reason, but whether players encounter them in the campaign, Spec Ops, or both remains a mystery. Fans will just have to wait for the Call of Duty: Modern Warfare release date later this month to find out for sure.

Beyond the campaign and Spec Ops, the third piece to the Call of Duty: Modern Warfare puzzle is of course the franchise's celebrated versus multiplayer. The Call of Duty: Modern Warfare beta was met with general enthusiasm from the community, but we'll find out if it lives up to the hype once the game launches later this month.

Call of Duty: Modern Warfare launches on October 25 for PC, PS4, and Xbox One.