The Rhineland - S1.E8

The team investigate paranormal activity in Germany's Rhineland. At the Rheinfels Castle, which has a notorious underground prison and tunnel system, they witness a mysterious flash of light and hear strange voices. After becoming lost in the labyrinth of tunnels, Kay hears his name called out, by whom he doesn't know. Next they explore a 11th Century castle known as Burg Reichenstein where Ian makes psychic contact with what he believes is the ghost of a headless man - and the team are under threat.