Especially that is when he needs to steal diamonds to rescue his kidnapped son, gratefully running through the London underground and up many flights of steps to escape from someone who was following him to get the diamonds back. The caper begins when his son and a friend skip school and end up on private property where there are warning signs posted, and after they are caught, they are basically tossed into the back of a truck like sacks of potatoes. The other boy is released but Michael Caine's son is kept behind and he must break into a private home, find exactly where the diamonds are, break into the desk and then run away with them to get them to the people who demanded that in the first place.

Once again, John Vernon is planning a truly despicable villain, the type that you want to see get his comeuppance, so pompous and creepy that it will be a great thrill when he does. Delphine Seyrig, Janet Suzman, Donald Pleasence and Clive Revill are others involved in this odd plot, a convoluted Thriller that takes a while to get off the ground. It finally begins to get exciting after Caine gets his hand on the diamonds, gets into the tube and has to find a way to avoid getting caught. The man chasing him even knocks somebody off of an escalator in order to catch up to Caine. As a British intelligence officer, Caine is already involved in the effort to stop a bunch of arms dealers, so it's not a surprise that the people he has to get the diamonds to end up being involved in that as well.

Convoluted for sure, but as the action gets going, the audience gets into it. Under the direction of Don Siegel (who directed a bunch of Clint Eastwood action thrillers),this has many moments of excitement, but there are also many slow-moving moments as well. Caine is always exciting to watch, and his performance is rather cool as if he'd rather solve them case he's working for then get his son back. He does have a great gift for mimicry, at one point imitating Donald Pleasence. It's definitely a curiosity with great photography and terrific London locations, but it's another 70 Thriller that probably was good as a novel yet transfers awkwardly as a film. Probably also better on a big screen where you are forced to pay attention rather than on home video where it's easy to become distracted when you are bored.

Two English boys are kidnapped by a criminal crew. One of the boys is the son of British intelligence officer Major Tarrant (Michael Caine). Cedric Harper (Donald Pleasence) is his boss and Sir Edward Julyan (Joseph O'Conor) is the head of MI6. Tarrant is in a meeting with them and others when he gets a call from his wife. Their son has been taken and ransomed for diamonds. Eventually, he has to battle both sides to get his son back.

While I like the premise, I am taken back by two issues. First, I got confused by several scenes in the movie. It's possibly due to my stupidity. I don't know the reason for the naked picture session. When the second boy shows up in the hospital, I assumed him to be the Tarrant boy. I kept losing track of the characters. The plot seems simple but I couldn't catch every scene. The second issue is Caine. I never get a sense of terror, anger, tension, or trauma coming from Major Tarrant. In fact, one scene has him making a joke wink as he makes an escape. The performance lacks the needed desperation. It doesn't fit. He's doing it wrong or the directing is wrong. I still like the premise but the execution is off overall.

Clinical and calculating top British agent Major John Tarrant (adroitly played with deceptive calmness by Michael Caine) goes after the ruthless gunrunners who have kidnapped his son. Moreover, Tarrant further suspects that one of his colleagues might be involved in said abduction.

Director Don Siegel keeps the involving story moving along at a steady pace, maintains a stark no-nonsense tone throughout, and stages a few exciting action scenes with trademark skill and precision. Moreover, while this film might be a bit lacking in tension, this is nonetheless more than compensated for by a wealth of tasty incidental details and a wickedly amusing sense of sharp self-mocking humor. The sound acting by the tip-top cast rates as another substantial plus: Donald Pleasence as quirky superior Cedric Harper, John Vernon as the coldblooded McKee, Delphine Seyrig as the saucy Ceil Burrows, Clive Revill as pesky copper Alf Chestermann, Joss Ackland as the shifty Chief Supt. Wray, Janet Suzman as Tarrant's fed-up wife Alex, Joseph O'Connor as the disillusioned Sir Edward, and Catherine Schell as the tart Lady Melissa Julyan. Leigh Vance's smart and intricate script shows with chilling lucidity the severe emotional price one must pay for being part of the pitiless spy business. Roy Budd's cool funky-jazzy score hits the right-on groovy spot. Ousama Rawi's crisp widescreen cinematography provides a pleasing picturesque look. Well worth a watch.