Old Bones

DCI Bill Slider's out of favour in the force - for accusing a senior Met officer of covering up an underage sex ring. As a punishment, he's given a cold case to keep him busy: some old bones to rake through, found buried in a back garden, from a murder that happened two decades ago, and with most of the principal players already dead.
Surely Bill Slider can't unearth anything new or shocking with these tired old bones?
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