After a seven year hiatus, Inspector Harry Callahan returns, his .44 Magnum handgun blazing, bodies piling up all around him, and an assortment of bad guys realizing that he may be getting older, but he certainly isn't getting any cuddlier.
Meanwhile, Inspector Harry Callahan is having a busy few days. First he disrupts a restaurant robbery by killing all but one of the heavily armed robbers. Then when another group of gangsters tries to kill him in a drive-by bombing, he lobs back their own Molotov Cocktail and dispatches them into the bay. Finally, Callahan deludes an aging crime boss into having a heart attack, which results in another bunch of goons coming after Callahan with machine guns; he kills them all. To end the mayhem, Callahan is sent by his superiors to San Paulo, presumably to follow-up on the leads of Spencer's first victim, but really to stop the carnage in San Francisco.
What is meant to be quiet time for Harry in San Paulo quickly turns into a serial killer investigation, as Spencer ups the pace and successively eliminates her victims. Callahan is soon on her trail, but he also encounters Parkins and her troop of ugly thugs; worse still, there are connections between Parkins and San Paulo chief of police, so Callahan gets precious little support in stopping the bloodshed. Dirty Harry is finally faced with his greatest dilemma: deciding what exactly is justice, and when are revenge killings justified, if ever.
Sudden Impact matches, and in some ways improves upon, the original Dirty Harry (1971). Joseph Stinson's script introduces a range of villains and foes worthy of Callahan's attention, and in Jennifer Spencer, the series gets its most intriguing killer. Both a victim and an assailant, and with Locke perfect in the role, Spencer has the deepest back story of any criminal faced by Harry, and presents him with his most twisted moral quandary. What Spencer is doing is self-defense, but 10 years after the fact. Her victims deserve their fate, but she is delivering frontier justice. Does she deserve Callahan's sympathy or his rage?
Sudden Impact bravely takes Callahan out of San Francisco for the second half of the film, the only time in the series that he leaves his home town. The risk works, and in San Paulo Harry is a big and prominent fish in a small but infected pond, and he perfectly attracts the attention of all criminal classes.
Stinson also peppers the script with memorable one-liners and dialogue exchanges, including the "Go ahead, make my day" tag line and the brilliant "dogshit" tirade in the courthouse elevator. Meanwhile, Eastwood directs with a panache not seen in any of the other series entries, and his back-lit entry into the climactic scene at the San Paulo boardwalk is an absolute gem.
Sudden Impact marks the welcome return of an old friend: he is back to prove that although the battlefields are new, the old methods still work just fine.