Episode 7819 ( 9th March 2012 ) Plot . Under relentless questioning , Peter admits to the police that he was drunk and had now idea where he was when Frank was murdered . On hearing they are not yet in a position to charge him , he leaves immediately . Karl whisks Sunita off to the casino . Rita returns home with Dennis to drop his bags before they head off for the Rovers . Lewis arrives for work at the bistro . Gail initiates an accusation about the missing £50 . Lewis tells Nick that it wasn ' t him , but he is clearly believed guilty , so he resigns . Peter arrives back on the Street , blameful towards Carla as her plan didn ' t work . He tries to get Ken to allow him to see Simon , but Ken refuses . Peter accuses Carla of thinking he killed Frank and refuses to go home with her . He goes to the pub . In the Rovers , Rita and Dennis announce their engagement to Norris , Mary and Emily . Norris is openly disapproving and leaves . Stella reluctantly serves Peter who is soon joined by Ken who urges him to rejoin his support group . Anne emerges from the factory troubled and informs DS Nash that the only copy of the new contract has mysteriously disappeared , managing to convey to him the significance of Carla retrieving the document . In the bistro , Gail tells Audrey about Lewis and the missing money . Audrey considers the expensive bracelet he has just given her and leaves to confront him . Nick waits on Eileen and Paul who are trying to enjoy a night away from caring for Lesley . Paul cannot relax until Eileen points out that Lesley needs a break from him too . In the Rovers , Audrey confronts Lewis about her suspicions over where he got the money for the bracelet . Lewis is crushed but tries to maintain his dignity . Anne arrives and finds Sally , Sean and Beth together . Anne points out that the missing contract signals the end of their employment and is affronted when they express their distress at losing their jobs in the face of her far more significant losses ( Frank and her husband ) . Sally follows her to the ladies toilets to console her . DC Grant and DS Nash are in the police investigation room , discussing the results of the finger print analysis on the whisky bottle ; they leave to make an arrest . Back at the Rovers , Emily , and Mary toast the happy couple . Sean leaves dejected and Beth decides to hit on Lewis . Eva returns to the pub laden with bags ; she ' s been shopping for the bistro . Karl and Sunita leave the casino and return to the Street . They have had a great night out and both agree not to mention the evening to their partners . Eva arrives at the bistro , and reveals it was her who took the £50 from the till ; Nick didn ' t notice her IOU . Audrey exits to try and make it up with Lewis . Carla arrives at the Rovers where Peter is still drinking . Audrey arrives asking Stella if she has seen Lewis . Stella points her towards the bus stop . Anne is now bolstered by whisky and confronts Carla , accusing her of stealing the contract . An enraged Carla protests her innocence just as the police arrive to arrest her . Audrey finds Lewis at the bus stop but he refuses to return with her . A distraught Audrey watches the bus pull off and then turns to witness Carla being driven away in a police car , a devastated Peter in pursuit by foot . Anne looks on triumphantly . Rita finds Norris licking his wounds in The Kabin , but he rallies when she asks him to make a speech . Shell - shocked Carla arrives at the police station and is escorted to a cell .