Three important items. Two major guest stars. One vital task.

The May 18 season finale of Supernatural - titled "There Will Be Blood" - will feature a couple of popular returning characters, along with a single task for Sam and Dean to accomplish. What, exactly, can fans expect from the installment?

The CW has released the official synopsis for the season seven ender and we've posted it below. Consider yourself sufficient spoiler warned...

In order to defeat Dick Roman and the Leviathans, Sam and Dean must locate three key items. Castiel helps with one but for the last objects, the Winchesters must face two of their strongest opponents – an Alpha and Crowley. Meanwhile, Bobby tries out a new ghost trick that ends up being very dangerous.

As previewed above, Supernatural welcomes Felicia Day tomorrow night for the episode "The Girl with the Dungeons and Dragons Tattoo." Return to TV Fanatic shortly after it concludes for a detailed review and react now to these season finale teases.

NOTE: My apologies. This description is for episode 7x22, the penultimate installment, NOT the season finale.

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