Monday looks to be the biggest Heroes episode of the season. Titled "Four Months Ago," it will review how our favorite characters ended up where we found them to begin season two.

Here's the official preview:

When the clock turns back four months for all of the Heroes, Nathan pays a terrible cost for his heroic actions. While Peter survives his detonation over New York City, the Company "bags" him as a threat to the world, eventually leading to violent confrontation with Elle (Kristen Bell) and the Haitian (Jimmy Jean-Louis).

[youtube]http://www.youtube.com/watch?v=XnbIA0D010M[/youtube]

D.L. (Leonard Roberts) makes the ultimate sacrifice for Niki (Ali Larter) and Micah (Noah Gray-Cabey). Maya (Dania Ramirez) horrifically manifests her dark powers for the first time, driving her and Alejandro (Shalim Ortiz) to America for help.

A mysterious, yet familiar face is introduced.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.