Few things are more frustrating to a film buff than seeing an otherwise good movie marred beyond redemption by a disastrous ending.

While I would never reveal what happens in the last act of the sometimes contrived military courtroom drama "High Crimes," I will say it throws five and a half reels of good acting and directing out the window for a cheap shock-thriller finale that 1) requires off-the-scale suspension of disbelief and 2) casts doubt on the validity of the entire plot.

In the first hour and 45 minutes Ashley Judd gives one of her strongest performances (in an idealized role) as a aggressive (but, of course, playfully feminine) defense attorney who abandons her promising career at a San Francisco law firm (she was, of course, about to make partner) to defend her adoring husband (Jim Caviezel) when he's arrested out of the blue and put on trial in a secret military tribunal.

It seems this warm, wonderful man (whom the film spends a conspicuous 10 minutes establishing as the perfect husband) is in fact a special forces marine who went AWOL and changed his name after being accused of killing innocent villagers during a 1988 anti-terrorist operation in El Salvador (a mission we see vague flashes of in an unnecessary prologue).

Meeting with her husband -- whom she now thinks she may not know at all -- through a military prison's visiting room glass, Judd and Caviezel ("The Count of Monte Cristo," "Frequency") share a powerfully tearful moment that gives the picture early promise. The fact that director Carl Franklin (who made the fantastic "Devil In a Blue Dress") can re-establish in this one moment their love, their bond, their trust and her absolute faith in his innocence is a testament to the talent of the director and his stars.

Franklin steers the film on a strong course as Judd hires a washed-up former JAG core legal eagle (the great Morgan Freeman, riffing on the Donald Sutherland role from "A Time To Kill") to help her navigate military law. She's decided to defend her husband herself after seeing the deer-in-the-headlights, 20-something lieutenant appointed as lead council.

Hints soon surface of a conspiracy and cover-up (five potential defense witnesses are already dead) that may go beyond this El Salvador incident and into the highest ranks of the military elite. It's not long before Judd feels her life is in danger. Mysterious cars stalk her on the streets and someone breaks into the run-down house she's rented near the base to deliver an ominous warning and a thump on the head.

Most of the action takes place outside the courtroom, which begins to feel like little more than a backdrop. But this gives the actors a chance to stretch their characters' wings. Judd turns her tenacious, high-priced lawyer into an everywoman touchstone by embracing multiple layers of candid emotionality. Freeman's wise-but-wild charm is perfect for his role as her recovering-alcoholic mentor, who now makes a living defending off-base hookers arrested for soliciting.

Amanda Peet, who is always sublime in supporting roles ("The Whole Nine Yards," "One Fine Day") and lousy as a lead ("Saving Silverman," "Tomcats"), steals scenes as Judd's flaky sister who tags along from S.F. uninvited and hops in bed with the young marine defense attorney. And although you don't see much of him, Caviezel has a meaningful impact on the film's fervency with his resolute earnestness.

But the movie is littered with standard-issue red herrings and other unintentionally obtrusive hints that there's more to the story than meets the eye. When "High Crimes" finally puts all its cards on the table, the good performances and relative intelligence of the script are revealed to be nothing but a facade that falls aside for another hackneyed Hollywood ending.