The series now focused on the younger, dynamic Mogul field agents - the eponymous "troubleshooters" - like Peter Thornton, who flew around the world to "hotspots" to protect the company's interests.

The show's storylines concentrated on disasters such as explosions and earthquakes, company take-overs, racial and political tensions, the discovery of new oil fields and the negotiation of drilling rights.

Brian Stead, returning to Berlin for the first time since 1945 to oversee a natural gas drilling deal, finds his past coming back to haunt him in a nasty plot to discredit him by a rival company.

Today the legacy of The Troubleshooters lies in its bridging the gap between "quality drama" and populist entertainment and charting a linear path trod by later British television serials, such as The Brothers and Howards' Way.

The series struck a chord with the 1960s audience thanks to its format - a potent combination of the oil business, globe trotting power politics, corporate wheeler-dealing and sex.

[1] A previously missing episode from series two - "Birdstrike" - was returned to the BBC by a private collector in May 2010, with the assistance of classic TV organisation Kaleidoscope.

[2] Another episode previously missing from series two - “Is That Tiger, Man?” (Originally broadcast: 30 April 1966) - was announced in October 2023 to have been recovered with the assistance of Film is Fabulous!