Guest Stars Jason Merrells as David Blackwell Harriet Cains as Louisa Blackwell Christine Tremarco as DS Becky Gallagher Nicola Stephenson as Ali Blackwell Peter Ferdinando as Michael Collersdale Kelly Harrison as Susan Reynolds Max True as Joe Blackwell Nicholas Moss as Ben Sarah Smart as Megan Eleanor Samson as Gemma Underwood Macaulay Harewood as Dominic Twyler