The addictive comic-book action series “24” (8 p.m., Fox) ends its fifth “day” at the office. This season, arguably the show’s best, has taken a particularly grim toll on the cast.

Throughout the course of the day, we’ve seen CTU regulars Edgar Stiles, Tony Almeida and Michelle Dessler die under violent circumstances. And who can forget that the day began with President Palmer’s assassination?

The makers of “24,” like the brains behind “Lost,” have concluded their viewers can handle the sudden departure of beloved characters.

Season five also will be remembered for Gregory Itzin’s evocation of the sneaky and physically awkward President Logan. And, of course, we’ll remember Jean Smart as the pill-popping, gun-slinging first lady.

While always entertaining, “24” features plot holes large enough to sink a Humvee. Once Jack had the coveted recording of Logan’s transgression, why didn’t he download it onto his voicemail? Play it for Karen Hayes? Leak it to the Drudge Report?

What happened to Jack’s love interest from the first hour or two? Will her surly son re-enter the picture? And what about Kim and her unctuous, much-older boyfriend? Jack’s got some loose ends to tie up. And there are only two hours left!

¢ Kenneth Branagh narrates “The Man Behind Hitler” on “American Experience” (8 p.m., PBS). This chilling, engrossing film relies entirely on passages from the personal diaries of Joseph Goebbels, Adolf Hitler’s longtime colleague and the Nazi minister of propaganda. Combined with footage of the Nazi party’s rise and fall, “Man” offers a very personal survey history of the Hitler era.

It also chronicles Goebbel’s use of film, radio, print and other media to sell the Nazi message to the German people and to demonize the enemies of the party.

A perceptive portrait of power, propaganda and evil, “Man” will not soon be forgotten. But why is this story of a German, narrated by a Briton, appearing on “American Experience”?

¢ “Heavy: The Story of Metal” (8 p.m., VH1, nightly through Thursday) explores four decades of music over four hours. Tonight’s hour begins with Black Sabbath in the slums of Birmingham, England.

The documentary offers equal parts hedonism and theorizing. In episode three, the only one available for review, we are asked to contemplate or calculate the sheer number of Tommy Lee’s sexual conquests. In the next moment, we’re told that L.A.’s metal scene was either a product of, or a metaphor for, the glitz, glamour and excess of the Reagan era. No wonder they call it headbanger music.

Tonight’s other highlights

¢ Arthur’s last straw catches fire on the season finale of “The King of Queens” (7 p.m., CBS).

¢ A talk-show host basks in the glow of adoration as she surrounds herself with 50 famous guests on “Oprah Winfrey’s Legends Ball” (7 p.m., ABC). Postponed from last Monday.

¢ The four finalists create a new uniform for the staff of a hotel chain on “The Apprentice” (8 p.m., NBC).

¢ The clues to the Rimaldi puzzle come together on the two-hour series finale of “Alias” (8 p.m., ABC).

¢ Andy’s estranged dad (Charles Durning) visits on “Everwood” (8 p.m., WB).

¢ A mole may imperil the lab’s future on “CSI: Miami” (9 p.m., CBS).

¢ Allison has visions of a parallel life on “Medium” (9 p.m., NBC). She sees what might have been had she pursued a lucrative law career and married someone other than Jake. Season finale.