The Avengers (1961)

S04E05 Castle De'ath

What could be causing the sudden disappearance of all the fish along the Scottish coast? Is there a connection to the mysterious dead frogman discovered, displayed as if on a rack? Steed and Emma suspect a link, prompting them to visit Ian, the 35th Laird of Clan De'ath. However, their investigation puts them at risk of being captured by the gillies lurking nearby.