Take command of the Los Angeles, a powerful 688 attack SSN nuclear attack sub. Your top-secret mission: destroy a Soviet Typhoon-class missile sub. At periscope depth you scan a peaceful surface sea of merchant ships. You order a dive to 150 feet, activate the HUD (heads up display) and search the 3-D contour map for the boomer.

Sonar reports two submerged contacts at bearing 350. You load wire-guided torpedoes and hide under an ocean thermal layer...waiting. Navigation orders a waypoint maneuver to intercept the contacts. You creep through the water to avoid making noise.

Suddenly an active sonar ping vibrates through the hull. You, too, are being hunted! Your towed-array listening devices and audio analysis ID the target - a Soviet Alfa-class attack sub at 9.8 miles. You lock-on and launch a Mark 48 torpedo, then order a hard turn to keep him out of your baffles.

You wait. It'll take minutes for sonar to confirm the kill. You sweat out the time, hoping you and your crew make it through this mission alive...and that your Mark 48 sends the enemy to crush depth - and a watery grave.