When the DCI on the case goes into labor, Commander Clare Blake takes charge in the investigation of a dead 2-year-old girl found on the site of a now abandoned psychiatric institute. The girl has been dead for several years but the body was preserved in a tightly sealed drum and is well preserved as a result. She also has a cross branded onto her chest. The pathologist's report is inconclusive so the team starts to check medical records of former patients. Eric Thornton and John Littlewood figure prominently in hospital files, but when it's confirmed that Littlewood has died, the police focus all their effort on Thornton.