***WARNING*** This is a spoiler. Do not click on the spoiler tag if you don't want to be spoiled.
You've been warned!
Here it is:
Spartacus' plan to weaken Crassus' forces and gain the upper hand is threatened by potential betrayal.
You can read all the episode log lines for the entire series and up to episode 5 of War Of The Damned in the Episode Guide page. Remember, do not read if you don't want to be spoiled.
source: MSN Entertainment