The fact that The Doombolt Chase remains all but forgotten is surprising. Whilst it does not contain the uncompomising nihilism of the other named serials and their supernatural elements, by its very nature it is a serial which would lodge in impressionable young minds, perhaps even more than those mentioned previously. Whereas these were often rather cheap videotaped shows which relied on strong scripts far more than impressive visuals, The Doombolt Chase is an out-and-out action thriller, entirely filmed on location.

The writer of this six part serial was Don Houghton, creator of Scottish soap Take The High Road and contributor to shows such as CATS Eyes and Doctor Who. It is interesting to note that there are similarities between Doombolt and Houghton's second Doctor Who story, "The Mind of Evil", with both using extensive use of military hardware and similar plot (concerning stolen missiles). The early 70s saw the Doctor confined to Earth in the twentieth century working with a military organisation called UNIT, allowing the inclusion of lots of fights, stunts, Land Rovers and men in uniform in Doctor Who. With the popularity of this setting, it is not surprising that HTV wanted a slice of the pie with a military orientated series of their own.

The plot of The Doombolt Chase initially concerns the apparently motiveless ramming and sinking of a small boat by Wheeler, the captain of a Royal Navy ship, HMS Crescendo. His subsequent arrest and trial prompts his son, Richard, and his two friends, Lucy and Pete (the latter a junior seaman on the Crescendo) to find out why the sinking occurred.

The narrative then takes form of a chase. After his internment by the Navy, Wheeler orders Captain Vallance, his friend and defence counsel, to take his son to Edinburgh, ostensibly less the boat that he sank was a local fishing boat and his family becomes the target for repercussions. However, Richard is more concerned with proving his father's innocence. From Pete he learns that Wheeler was prompted into his action after receiving a message in "Spens Code". Richard recalls that this is a private code between his father and a friend called Spencer. After an attempt to leave to visit Spencer by road is foiled, Pete and Richard take Wheeler's yacht to make the journey by seam acquiring Lucy en route. During the journey they travel through the Navy's forbidden zone in the Bristol Channel where they discover a peculiar radio controlled boat. When they finally reach Spencer's house they find it empty; he has vanished leaving only a trail of blood. Discovering a map with a location marked they are drawn cross country to a lare country house. Here they discover technicians dressed in radiation suit like apparal working on a device consisting of two small parabolic dishes. This is being demonstrated by mad scientist Franz Bayard to a tactfully unidentified "foreign delegate" who is keen to buy it. The device is a superior version of the Doombolt, lynchpin of the Navy's coastal defence system. Using this, Bayard can direct a nuclear missile anywhere he wishes. It transpires that an important part of the Doombolt is a small radio controlled boat; it was this that Wheeler destroyed in an attempt to prevent Bayard getting control of it, but Bayard has a duplicate.

The remainder of the serial features lots of running around and various characters being captured and escaping, before an impressive climax featuring an attack by the Royal Marines on a small island in the Bristol Channel.

The Doombolt Chase features a cast made up of many well known actors; John Woodnutt as Spencer, Ewen Solon as office-bound Navy chief Admiral Lupin and Peter Vaughn as his lieutenant. However, the main characters were played by less well known actors; one Donald Burton as Wheeler, Andrew Ashy as his son and Shelley Crowhurst and Richard Willis as Lucy and Peter. Willis would later appear in the Doctor Who story "Full Circle".

Burton is excellent as Wheeler, and makes much of his part in the first four episodes when he has little to do but wait around for his court martial. It is in episodes five and six that Wheeler gets something to do, such as gallivanting around the Brecon Beacons hitting people in search of Bayard and his errant son. However, it becomes apparent early on that the three young leads were selected more for their ability of shin up drainpipes, ride motorbikes and leap over fences, rather than any acting skills.

The main villain of the piece, Bayard, is played by veteran actor George Colouris, who had appeared in the Pathfinders serials of the 50s. However, Bayard is permitted little in the way of character development other than "you know he's mad, don't you?" In contrast, possibly the most interesting character is Vallance, as played by Frederick Jaeger. Initially introduced as Wheeler's friend and defence counsel, he is later revealed as a traitor and Bayard's right hand. It is interesting that at the end of the serial both Bayard and Vallance escape, perhaps suggesting that a sequel was planned, although it never happened.

The serial does have some problems. The atmosphere in the first two episodes is often a little too Enid Blyton - "let's all run away and have an exciting adventure" - in contrast to the gritty atmosphere that arises from the use of the Naval hardware and James Bond style action. The action sequences in particular are effective, featuring a seamless blend of stunts, military co-ordination and stock footage. There is much hardware on display, including ships, helicopters and Land Rovers. The Doombolt itself is represented by a collection of satellite dishes, controlled by Bayard's mobile HQ (conventiently represented, one suspects, by the HTV OB van). There is a strange scene in which the power of the Doombolt system is demonstrated by the destruction of statue at Bayard's house. I'm not quite sure what the point of this is, since it is supposed to be a missile guidance system.

When compared to other HTV children's serials it is difficult to work out where The Doombolt Chase fits. While many of its contemporaries may be considered more adult in their outlook, the serial proved that the company was capable of diversity and could produce a series that is perhaps the very defintion of "action-packed".