1.9363 Views
A mysterious call from Special Branch leads Barlow into a cloak-and-dagger world which is, as Fenton warns him, ""shadowy, full of intrigue - and violent"".
First Air Date : Sep 15, 1971
Last Air date : Feb 26, 1975
Episode : 29 Episode
Season : 4 Season
Runtime: 50:14 minutes
Studio: BBC One
Country: United Kingdom
Cast: Stratford Johns, Derek Newark
