For nearly 400 years between 43 to 410 AD, the southern half of Britain was under Roman occupation. During that time, the Roman emperor Hadrian ordered the construction of a wall to separate the Roman frontier from the “barbarians” of the north. Spanning 73 miles, Hadrian’s Wall is now a UNESCO Heritage Site and considered by some to be haunted by the ghosts of Roman troops. Tonight on #GlobalInvestigator, join robriggle as he heads to Northern England to investigate the mysterious disappearance of Rome’s ninth legion. Tune in at 11P.