E1 - The Mysterious Death on the Underground Railway

Aired: January 29, 1973

Polly Burton assists in soving the case of a grl found dead on a seat of an underground train.

E2 - Five Hundred Carats

Aired: February 05, 1973

Inspecor Lipinski investigates the theft of a 500 carat diamond.

E3 - Cell 13

Aired: February 12, 1973

Professor Van Dusen, the 'Thinking Machine', boasts that he can think his way out of a prison cell. When he is locked up he is given the chance to prove that he can escape by the power of his mind alone.

E4 - The Secret of the Manifique

Aired: February 19, 1973

Laxworthy and two friends secure the safety of the plans for the first torpedo to be used by the French navy.

E5 - The Absent-Minded Coterie

Aired: February 26, 1973

Valmont has to help break a ring of counterfeiters.

E6 - The Sensible Action of Lieutenant Hoist

Aired: March 04, 1973

Lieutenant Holst of Copenhagen has to help a Russian countess who claims her brother-in-law aims to kill her.

E7 - The Superfluous Finger

Aired: March 11, 1973

Professor Van Dusen must find out why a young woman had a perfectly healthy finger cut off by the eminent surgeon Prescott.

E8 - Anonymous Letters

Aired: March 19, 1973

In turn-of-the-century Vienna, Dagobert Trostler investigates a poison pen case.

E9 - The Moabite Cypher

Aired: March 26, 1973

Dr Thorndyke has to decypher a code to stop a plot to assassinate a Russian Grand Duke.

E10 - The Secret of the Foxhunter

Aired: April 02, 1973

William Drew of the foreign Office investigates an unusual crime.

E11 - The Missing Q.C's

Aired: April 09, 1973

Charles Dallas is led into a strange and sinister adventure in the aftermath of a sensational murder trial.

E12 - The Looting of the Species Room

Aired: April 16, 1973

Gold disappears from the strongroom of the RMS Oceanic and its purser, Mr Horrocks, tries to discover what has happened.

E13 - The Mystery of the Amber Beads

Aired: May 07, 1973

Hagar the Gypsy sets out to prove that Detective Sergeat Grubber is wrong about who killed Mrs Arryford.