The series stars Sarah Lancashire and Phil Davis as the principal characters, Rose Linden and Marion Maloney, who are investigators working for the fictional Criminal Justice Review Agency, who take on claims of miscarriages of justice, assessing whether there are grounds to reopen old cases.

Rose Linden is portrayed as strong-willed and sometimes reckless; a woman who likes to follow her instincts and play hunches, who often comes into conflict with authority.

Maloney is by-the-book and a little grey, and he finds working with Rose dangerous but addictively exciting.

[1] Additional cast members include Nisha Nayar, Susan Brown, Anne Reid and David Westhead.

Guest stars throughout the series run include Tara Fitzgerald, Danny Dyer, Tiana Benjamin, Andrew-Lee Potts and Neil Dudgeon.