Episode 20: The Fountain of Youth Affair
Original Airdate: February 7, 1967

Mark and April arrange to meet an informant who claims a politically important woman is in danger at Rejuvena Isle. However, two killers with an odd gun shoot her first. When Mark and April arrive, the informant is dead, having expired from old age though a very young woman. It is discovered that Baroness Blangstead offers the fountain of youth, her wonder drug, to those who can pay her price: Official Secrets.

Episode 21: The Carpathian Caper Affair
Original Airdate: February 14, 1967

Thrush Agent Mother Magda is plotting the elimination of world leaders and planning to replace them with exact doubles. Mark loses the tape with all the details as to how it will be done. April and Mark must recover it immediately.


Episode 22: The Furnace Flats Affair
Original Airdate: February 21, 1967

The Utter Anguish Gold Mine is up for grabs when the owner dies. The mine contains a huge vein of Triterian crystals that can be used to make death beams from laser light. Thrush and UNCLE are VERY interested in acquiring the mine.

Episode 23: The Low Blue C Affair
Original Airdate: February 28, 1967

A retired gangster from Chicago is second in line to rule a small Mediterranean country. He assassinates the Duke leaving only one person in his way, Major Stella who is currently saving souls in London. Mark and April are sent to persuade her to save her country.


Episode 24: The Petit Prix Affair
Original Airdate: March 7, 1967

A French School for Civil Administrators always plans a commando exercise for its graduating students. Waverly knows that there is some kind of hijack being planned so he sends April and Mark to investigate.


Episode 25: The Phi Beta Killer Affair
Original Airdate: March 14, 1967

A former classmate of Waverly's owns a bodyguard service. When one of the clients is murder, only the body guards are present but they don't recall it happening. Waverly sends April and Mark investigate.


Episode 26: The Double-0-Nothing Affair
Original Airdate: March 21, 1967

Thrush has developed a new mobile force that enable them to disrupt UNCLE operations. Mark infiltrates the group and tapes their transmissions. He makes his getaway, hides the tape in his rented car, and contacts April but he is shot in the leg. The car and tape are stolen by a man who overhears his transmission to April. Mark is taken off the case; April is assigned the case.

Episode 27: The UNCLE Samurai Affair
Original Airdate: March 28, 1967

Waverly believes that a Japanese war criminal is active again. Mark and April go to Hawaii to investigate their only lead, his sister. When their informant is killed, it's obvious to Mark and to April that the sister is involved.

Episode 28: The High and Deadly Affair
Original Airdate: April 4, 1967

April poses as an airline stewardess; Mark is disguised as a big game hunter. Both are on board a plane carrying a number of scientists to a Council of World Scientists meeting. One doctor aboard has developed a substance that, carried by harmless birds, can cause slow death to humans. Also on the same flight is the doctor who has developed the antidote. Waverly fears a confrontation between the two hence April and Mark on the scene.

Episode 29: The Kooky Spook Affair
Original Airdate: April 14, 1967

Mark inherits a home in England. April, who is key witness against a Thrush Agent, has been threatened. Waverly suggests April stay with Mark until the trial. Unfortunately, a plot is afoot to kill Mark so that the stately home can be inherited by another relative.