Determined Expression

This is a basic way to show a character's determination. In a dangerous situation, rather than head for safety or rush madly into the fray, some will approach the problem with a measure of deliberation. Their expression, if not Dissonant Serenity, will be this: brow furrowed, eyes often narrowed, lips tight, body tense. The effect may be enhanced by a Kubrick Stare. The result is similar to a Death Glare, but less extreme, and usually not directed at a specific individual.

Often graces the face of the chronic Determinator. It may be used on a previously non-threatening character to indicate that they have become serious or just Took a Level In Badass.

Like many tropes, this one suffers an inverse relationship between prevalence and effectiveness. A character who sports this look all the time is likely to fall prey to The Worf Effect, whereas one who only wears it once or twice, especially near the climax, will be more effective.

Often combined with an Unflinching Walk. Compare Death Glare, contrast Oh Crap.

Anime and Manga

 * In Afro Samurai, the young protagonist takes this expression very shortly after seeing his parents killed. This is the moment he is truly destined to become a badass.
 * Vash (above) looks like this whenever he drops his facade of idiocy and decides to get serious. Only to be expected from a man who's byword is determination.
 * Tengen Toppa Gurren Lagann takes this trope Up to Eleven in typical style. These happen, of course, throughout the series, but the crowner comes in the grand finale, when a stunning The Reason You Suck Speech from the Big Bad is countered by Determined Looks from people across the globe, as they send a Combined Energy Attack to the titular mech and simultaneously kick off a Last Episode Theme Reprise.
 * The extremely Badass Ronin Nanashi from Sword of the Stranger. When he gets that I-will-kill-you expression on his face, you know you're fucked.
 * In the Soul Eater anime, there's a shot of each of the main characters displaying one in turn just before the first battle for the B.R.E.W.
 * Yu-Gi-Oh: Kaiba is the master of this trope. Also, if Yami Yugi does this instead of making a speech, things are about to get intense. The gang has been known to call this his "game face". For Joey, this is usually the signal that you've managed to flip his switch from Plucky Comic Relief to Let's Get Dangerous. Crowning moments of awesome never fail to ensue.
 * Goku, from Dragonball has this right after turning Super Saiyin for the first time, except his arms are akimbo.
 * Whenever somebody gives him the "Because Destiny Says So" speech or the "live to fight another day" speech when he's faced with a difficult opponent, Guts from Berserk always gets this look. A very memorable moment was when Guts faced Griffith for the second time in order to win his freedom from the Band of the Hawk.

Live Action TV

 * Done mostly through body language, Sally Sparrow does this in the Doctor Who episode, "Blink", after Billy Shipton dies, with a correlated change in soundtrack. She immediately takes initiative within the plot rather than just reacting as she has been.

Video Games

 * At the end of De Blob 2, the normally cheerful and carefree Blob gets quite serious after Comrade Black uses . He gives Comrade Black's surveillance camera a look which very clearly says, "I am coming for you, and you will pay for this".