Thekla plays Gina Hawkes, a lawyer who visits Philip Glenister's solicitor Harry Venn, asking him to help her find a key witness in order to clear her client.
Gina's motives are mysterious and unclear as she re-introduces Harry to aspects of a criminal past he would rather forget.
The series is directed by Niall MacCormick.
Hidden begins on Thursday October 6th at 9.00pm on BBC1.
A preview trailer can be viewed below.