Just as things appear to be settling for Carol and Yates, they are given an unwelcome surprise when Cathal returns.

Tonight's episode of Fair City is sure to cause some tension between the happy couple as the villain reveals all to Carol.

The last time we saw Cathal, Yates blackmailed him so to get him out of Carrigstown and out of his life.

Cathal's meddling became too much when he burst through Carol's front door, threatening her.

Fortunately, her hero Yates came just in time to push Cathal away.

The inspector seemed happy when Cathal left, but it's all about to come crumbling down.

Coming up in Tuesday's Fair City, Deegan is shocked when Cathal reveals that Yates was blackmailing him when he was acting as a confidential informant.

Deegan tells Cathal this is a "very serious allegation" and Cathal tells him: "He threatened to expose me to my associates unless I left town."

Yates tries to state his case, but Deegan won't let him talk.

"I have to ask you to leave the room", Deegan tells Yates, leaving Cathal looking smug.

Is Yates in more trouble than ever before? What will happen with Carol - will she use the information she has on Cathal against him?

Find out what happens on RTE One at 8pm tonight.