'Jigsaw' is an episode which sees Jack Regan at his most persistent and self-sufficient. Disregarding advice and/or instructions, and even keeping colleagues out of the loop to some extent.
Regan's handling of the Eddie Boyse case is characteristic of his tendency to keep plugging away, but also of his ability to approach a job on more than one level. His grasp of psychology and human nature allows him to apply pressure. A case of knowing which buttons to press with people, as it were. This is all allied to ordinary detective work. Even if the material evidence does not fully emerge, other avenues may produce a result.
The plot is interesting, and actually not that outlandish, in terms of the carrying out of the robbery itself. The one false note for me was struck by the involvement of Boyse's MP ; I don't think that those scenes really worked.
Thaw and Waterman are on fine form as always, and there are solid performances from Del Henney and Sheila Gish.
This is also an illuminating episode from the point of view of the relationship between Regan and Carter. The sergeant is cast in a very much subordinate role here. He harbours, and occasionally expresses, doubts about some of Regan's methods, but ultimately respects his superior's nous, determination and capacity to produce results.
Although it has one or two flaws, this is a good episode.