The police arrive at Wishing Well and inform Lisa that there's not enough evidence to go to court, so the investigation into Derek is closed. Lisa is devastated, while Zak is furious that there's no chance of getting justice for his wife. As Lisa heads to work, Zak broods and furiously storms towards the van. Sam alerts Lisa to Zak's behaviour and she races to Derek's house, where an irate Zak is banging on the door screaming threats (thetvdb.com)