It's come down to this on season six of Dexter.  One final episode to see if our murderous hero can stop Travis Marshall before he completes his tableau, takes who-knows-how-many-lives and brings on the End of Days. In his warped mind, at least.

Will Dexter track DDK down in time? Will Harrison become the next loved one to perish as a result of Dexter's Dark Passenger? And how will Deb handle the crazy new feelings she developed this week for her step-brother?

All will be revealed on Sunday's "This is How the World Ends," the season six finale teased below. Watch and get ready now:

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