Thank you, Jack. I have just found this in a review of episode three.
Patrick and Sally kill Rebecca after she discovers them in bed. The next morning, Sally pretends to be Rebecca while Patrick dumps her mutilated body in a park. Hannah Markham learns about her father’s affair and skips school. Gabriel and Shepard investigate the latest acid killer crime scene but tacitly agree that the latest body might be the work of a copycat. Patrick is pulled in to the station to be informed of his wife’s murder and is held under vague pretences late into the night. But instead of focusing on the case, Gabriel is tearing up London’s illegal rave scene looking for his missing daughter. He and Shepard find Hannah, while Patrick and Sally are burning all the incriminating evidence. And since we didn’t hear about any of this in the first two episodes, it looks as if they’ve got away with it.