Dr. John Brady is working at the Castle Hill government laboratory investigating the nature of refraction - his experiments achieve success when he is able to make a rat become invisible - but a leak in the containment chamber releases the radation into the lab, and Brady finds himself rendered completely invisible as well. At first put under lock and key by the government, he escapes and runs to his former colleague Dr. Crompton for help, but finds that the powers of invisibility have the potential to corrupt... The first episode begins very quickly, with Brady becoming invisible in the first moments. Fortunately they give time to introduce and develop Brady and his family before the action starts - already however, the 25 minute runtimes of these episodes starts to show itself, and the pacing does seem a little rushed.

When a British agent is captured in a hostile Middle Eastern country, the government fear that his knowledge of the resistance movement there could place all its members in jeopardy. They call on Brady to rescue the agent from a tightly guarded military hospital. The second episode of the series sets the tone for many of the following entries, with Brady being called on to help someone in trouble. In this case, unlike some of the later episodes, they give Brady a convincing reason to get involved, and makes full use of his invisibility. One of the best episodes.

Brady is working hard to find a cure for his invisibility but needs a human volunteer. He is tricked into travelling to the house of the exiled South American industrialist Raphael Constantine. Hideously scarred by a grenade the man appeals to Brady to use him in the experiments as he yearns for invisibility. However, it soon becomes clear that Constantine has a more sinister purpose in mind for his powers... The third episode fortunately goes for a different approach and is one of the most inventive episodes in the season, although by the end of the episode the government agents seem unconcerned to reveal Brady's existance in public.

An outspoken Russian scientist speaking in London is kidnapped by secret agents and locked up in the embassy. Brady follows her and breaks into the embassy before beginning a diplomatic attempt to have her freed. When this fails he sneaks her out of the building to his own house, but finds that the Russian ambassador is not going to give up the chase easily... Brady again getting involved in other people's problems, although fortunately he does have a good reason to get involved this time (the scientist has been working on refraction and could be the key to getting Brady visible again) and the episode makes full use of his invisibility. A quite unpredictable episode and well written, it builds to a rather exciting climax with some of the best effects work of the series.

After a serious car accident witnessed by many people, the government reveal Brady's invisibility to the press and he becomes a near-celebrity figure hounded by the media. Meanwhile the friend of his young neice begins to suspect that her stepfather is planning to murder her mother for the inheritence and pleads with Brady to help... After the interesting opening the episode falls into the trap of many of the Invisible Man stories, a typical detective story with Brady rather awkardly inserted, and getting to do very little that a completely visible person couldn't have done. Fortunately it does boast a rather thrilling climax sequence.

Barbara Crane, a respected theatre actress, finds herself the subject of bribery after accidentally running down a man on a clifftop road. Worried by the events she starts to perform badly, and a suspicious Brady decides to investigate further, discovering that there is more than simple blackmail going on... This sixth episode is another example of some of the problems that begin to emerge later in the series. Although a cleverly written mystery story, the Invisible Man himself is very crudely inserted and gets little to do. Unfortunately the episode's short runtime prevents enough characterisation being developed, for the story to actually be solvable by the audience; the writers also seem to miss a key point - when Brady's foolish actions lead to a man being killed, he barely bats an eyelid.

A Russian sailor makes a bid for freedom from a trawler at anchor in a British harbour, but is soon captured and taken back to the ship. The head of the refugee committee appeals to Brady to help them and although reluctant to assist, he soon decides to sneak on board the ship and find out what he can do to help - however, it soon turns out that Brady has been set up, and he is ambushed by the sailors as the ship heads back towards Russia. Often during the series, Brady seems to consider himself a sort of super-hero, and episodes like this show that he is rather vunerable, in this case to a new Russian technology based on radar, that lets them see the Invisible Man - it is only a pity that the writers did not exploit this particular theme more. A decent episode and the first for a while that revolves around Brady himself.

A group of criminals raid an important British atomic laboratory and photograph some key documents onto microfilm. When the customs officers quickly clamp down on passengers leaving the country, one of the men hides the film in the mink coat of the ventriloquist performer Penny Page who is flying to Paris. When Brady's sister Diane witnesses this, the pair find themselves drawn into a deadly game as the criminals try to get the invaluable film back from Mrs Page. Another fine story, remniscent of a film noir, into which Brady and his sister are rather poorly written and get little to do.

When an airline pilot is framed for importing drugs into the country, he phones his old friend Peter Brady for help. Before Brady arrives however, the pilot is shot and badly injured in front of his wife, who is blind. Brady helps the police with their investigations and devises and elaborate plot to find the killer... Although seemingly just another detective story packaged as an Invisible Man epsiode, the story here takes full advantage of Brady's invisibility with a very inventive climax.

When the reformed career criminal is framed for an armed robbery and sent to prision again, he is determined to get free and prove his innocence and escapes 5 times before being recaptured. Curious about the story, Brady decides to investigate and helps the man to escape again to discover the truth behind the conviction... While Brady is often rather crudely written into stories, this episode has to include the most implausible reason to get the Invisible Man involved - reading of his story in the newspaper, Brady is so convinced that any man who can escape five times must be innocent, that he travels to the prision to help out. The rest of the story is a typical Brady as private detective storyline with very little on display that a fully visible detective could not have done.

Brady's fame leads to trouble when a group of criminals kidnap his young niece and hold her hostage - forcing Brady to commit a bank robbery. A rather inevitable episode, Bank Raid is well plotted although it suffers from the rather short run-time (the storyline had enough potential to be extended to a two part episode at least) and does have a rather terribly written and overly predictable ending.

When one of Brady's colleagues announces that he will not be returning from his holiday in Italy, and is seen using his mathmatical talents to win at roulette, Brady decides to fly out and convince him to return - but he soon discovers that Professor Owens is working to save his daughter who is being held hostage by the mob... Although another detective story, this time it is obviously written specifically for The Invisible Man and makes full use of his invisible talents for cheating in casinos. There is an interesting point when Brady's meddling again almost gets someone killed although as in Play for Death it is quickly brushed over.

After his bag of documents was stolen, Brady is kidnapped by a mysterious man who wants him to commit a murder - and to keep the unseen Brady in check, he has a vicious guard dog who can sniff out and catch even an invisible man. The potential for invisible mischief again crops up here, with the rather inventive concept of a dog being used to keep the scientist in check, even when completely invisible. Well paced and very dark it does leave the viewer wondering why there are not easier ways to have a man killed than kidnapping the Invisible Man. It makes for a decent conclusion to the first season.