In the upcoming episode of "Supernatural," audiences will get to see more supernatural creatures and a new case that will involve Cole.

According to a new preview released for episode 15, Sam and Dean investigate a new murder that involves a former soldier and suspected Khan Worm. As they investigate the case, they run into Cole, who has now abandoned his revenge-driven plan. Cole tells them that he was friends with the suspect and decides to join the investigation and also to make sure the Winchester brothers don't hurt the suspect.

The investigation goes awry when Cole is infected by Worm and it becomes unclear if the brothers kill Cole in order to stop the infection or if they manage to save him.

As the Winchester brothers continue the investigation, Sam continues to look for an antidote for the Mark of Cain after killing Cain. Sam becomes increasing upset about hunting when Dean shows him another weird case to investigate.

"Supernatural," now its tenth season, began in 2005 and tells the story of two brothers who follow in their father's footsteps as "hunters" fighting evil supernatural beings. The supernatural beings include monsters, demons, and gods that roam the earth.

The show stars Jared Padalecki ("House of Wax," "Friday the 13th") as Sam Winchester and Jensen Ackles ("My Bloody Valentine 3D," "Smallville") as Dean Winchester. The show has also stared Misha Collins ("Girl,Interrupted"), Jim Beaver ("Adaptation," "Next"), Mark Sheppard (In the Name of the Father," "Unstoppable"), Jeffrey Dean Morgan ("Watchman") and Osric Chau ("2012," "The Man with the Iron Fist").

Supernatural is filmed in Vancouver, British Columbia and surrounding areas. Before the series took off, it was in development for ten years. The show was created by Eric Kripke, who spent several years unsuccessfully pitching it, until WB decided to pick it up.

Season 10 episode 15 will air on Wednesday, March 18 at 9 p.m. on CW.