Based on the famous novel by Alistair McLean, "Puppet on a String" brings secret agent Paul Sherman, played by Swedish actor and singer Sven-Bertil Taube, to the Dutch metropolis of Amsterdam. It's his turn to hunt a drug-smuggling gang and a corrupt policeman, and it takes some victims and actions until he faces the main villain on a dark harbor site in a last fatal fight.
The dark streets and canals of Amsterdam are a perfect setting for this seventies' thriller, and the action and suspense work pretty well. There is an incredibly breath-taking motor boat chase through the canals which looks takes the car chasing action of "Bullitt", "Vanishing Point" and "French Connection" a bit further and has been copied by Dick Maas in his Dutch 1987 psycho thriller "Amsterdamned". There are some really scary and psychedelic scenes in the movie, and Piero Piccionis great sound track adds much weight to the picture (and has been reissued two years ago on CD). A great forgotten action movie!