Penny Branning is left horrified when she unearths a horrifying secret about Harry's missing girlfriend in Monday's episode of EastEnders (7:30 pm. See our TV Guide for full listings).
Fed up with being blackmailed by Harry Mitchell, Jack is determined to fight fire with fire and uses his police connections to delve into the case of Harry’s missing girlfriend, Shireen.
Penny, who is plotting against her own dad in a bid to teach him a lesson after he sided with Denise over the club crush at Peggy's, warns her on/off boyfriend Harry that her dad is putting pressure on.
Harry isn't happy after getting used to being the one to make the threats and tells Penny that she needs to get Jack to lay off or he’ll expose her part in the plot against him.
Trying to take control of the situation before it spirals completely out of control Penny convinces Jack to let her meet Shireen’s friend Felicity and attempts to warn her off.
However, nothing can prepare Penny for what she is about to discover, because Felicity’s account of what happened to Shireen leaves her chilled to the bone.
Later, the police arrive to arrest Harry, as Jack and Penny watch on. But before he gets in the car, Nicola Mitchell – Harry and Barney’s mum – arrives in Walford!
Elsewhere, Elaine is relieved to see Linda is back on the wagon and focused on recovery, but her positivity is destroyed when Bernie arrives back in Walford and is set on getting revenge for her brother's death.
As Linda tries to explain that she confessed everything to the police but they don't believe her, Bernie rages over Nish taking the rap and warns that neither of them will ever move on because of all the lies.
To make matters even worse, Bernie then stalks over to confront Suki, who tries a different tactic to calm her down - but will her plan work?
Phil is not in a good place and is getting increasingly annoyed by Teddy’s low-ball offer for Peggy’s and dismisses him, saying there are other interested parties.
Both Sharon and Kat separately try to talk to Phil, who is becoming more and more isolated from his friends and family. But Phil covers his emotions and refuses to open up to either of them - can they get through to him?
EastEnders continues on BBC One on Tuesday at 7:30 pm.