Isolation is a powerful tool for instilling fear. Staring down an overwhelming horde of supernatural foes with only a handgun at your side isn't enough; true terror dawns when you realize you are alone, and no one is coming to save you. Until recently, if you had told me that it was possible for "Resident Evil" to harness dread and desperation by giving players a competent ally who can bail them out of trouble, I would have rolled my eyes in thinly disguised disbelief. Now I've played "Resident Evil 5," and I believe.

The latest entry in Capcom's zombie-infested juggernaut pairs special agent Chris Redfield with Sheva Alomar, allowing you to play co-op through the entire game. If you think having a buddy in the field diminishes the stakes, think again; working with your partner explores new avenues of fear and intensifies every encounter.

It was terrifying to see a chainsaw-wielding, burlap-wearing freak bearing down on you, but wait until you see it happening to your partner only feet away. You'll watch through a sniper scope as an infected mob surrounds your friend and frantically lob grenades at hulking abominations to buy time for your partner to line up a clear shot.

The presence of another player transforms "Resident Evil's" signature style of combat into a harrowing mixture of tactics, cooperation and survival, all while retaining the same carefully crafted atmosphere of looming horror and anything-can-happen thrills. If you aren't playing "Resident Evil 5" with another person, you're really missing out not only on the best this title offers, but also on one of the best multiplayer modes in gaming, period.

Even if playing co-op isn't an option for you, the inventive game play and heart-stopping action still put "Resident Evil 5" ahead of the competition. The pacing is brilliant, with pockets of desperate combat and surprise encounters separated by almost enough time to catch your breath. One moment you're slinking through dark and abandoned mining tunnels and the next you're in a full-blown fire fight with tentacle-head zombies and dynamite flying from all directions.

It doesn't even matter if you aren't a diehard "Resident Evil" fan. The game play is much more of a draw than the convoluted narrative; once you start playing, you won't want to stop. The game leads you from one jaw-dropping moment to the next with remarkable ease.

If you opt for a single-player run-through of these events, the computer-controlled Sheva is surprisingly competent. The action never degenerates into an escort mission. Sheva can take care of herself, but she is generally unobtrusive and only occasionally helpful. This lends the single-player experience more of a "Resident Evil 4" flavor, which delivers a different but still mesmerizing brand of white-knuckle game play.

While retaining much of the spirit of the previous entry, "Resident Evil 5" is unquestionably an evolution. A revamped inventory system keeps you in the moment by eliminating the heavy item-management requirements, and the control scheme ditches most of the archaic holdover mechanics from the series' past.

"Resident Evil 4" was among the best games of the last generation, setting unprecedented expectations for the next entry in the series. "Resident Evil 5" succeeds in staying close to what gamers loved about the previous title, but it also takes risks that pay off in unexpected ways. Co-op changes your approach to survival horror, and the masterful pacing ensures you never take your eye off the action.

Like its predecessor, "Resident Evil 5" is destined to be remembered as one of the best games of its time.