This mission plays similarly to The Gorge Base in the original Airforce Delta in that you have to fly through a gorge and avoid making contact with the rock face. You also have to avoid flying too high as the airspace above the gorge is saturated with the enemy's aerial defense network. The first part of the gorge veers immediately to the right so fly in that direction and be careful of the ships in the water firing bullets and missiles at you. Continue flying through the gorge and it will veer to the left. Not far ahead is the first of six bridges you must destroy. Flying under the bridges while destroying them is risky as the remains can fall on you. Around the bridge are several gun pods and missile-launching P.A.C.-3s and more ships in the water. Up ahead is another bridge. Take that out as well and continue flying through the gorge. It will veer left again and further ahead, it will veer right. Watch out for the ships in the water and take out the two bridges up ahead. Continue flying through the gorge and you'll reach the fortress with the last two bridges on the left and right, eight gun pods around the fortress you have to destroy, and numerous ships in the water. Once all required gun pods and bridges are destroyed, the mission is completed.
- Destroy all targets.
The reward for this mission is 10,000 credits plus a variable amount depending on the number of enemies taken out. All enemies in this mission are ground targets and in this game, taking out ground enemies with bullets does not double the amount. Bellona Airbase with the mission Defending the Zayno is unlocked. Pursuit Across the Sky is also unlocked at that airbase if any three missions are also completed. The Tornado F3 is unlocked for 190,000 credits at Bellona Airbase while the Kfir C7 is unlocked at Agakles Airbase for 180,000 credits. In the PAL version, the Su-24M Fencer D is unlocked at Bellona Airbase for 210,000 credits as well.
We have just received word from the Intelligence Division. There is an enemy fortress on a bridge in the upstream portion of the Cayenne River, near the foothills of Mt. Megalith. Your mission is to cut off the United Forces supply route on the Cayenne River. You must attack and destroy the fortress and seal off their transport routes on the river. It looks to be a difficult mission, but success is vital. The air space above the gorges is saturated with their aerial defense network. We recommend that you fly within the gorge, and be on guard against making contact with the rock face. Over and out.
Delta Leader: (When mission is selected on the map) Our mission this time is to neutralize the bridge fortress. The enemy has lots of firepower here. Also, watch out for the buildings. The air space above the gorges is saturated with their aerial defense network. We recommend that you fly within the gorge, and be on guard against making contact with the rock face.
United Forces Ship Captain?: This is patrol craft 0203. Requesting permission for passage.
Base Control?: Patrol craft 0203, passage is granted. Many Allied Forces attack fighters currently closing, Hurry up. Enemy craft sighted. Distance: 6800, position: 0120, angle of elevation: 22 degrees. Commence attack!
[pre-mission cutscene ends]
[no dialogue during mission]
Main article: Through the Valley of Death/Soundtrack
- The name of this level is a reference to a popular Air Force phrase; "Though I travel through the Valley of Shadow and Death, I will fear no evil, for I am at 80,000 feet and climbing.", which, in turn, is based off of a biblical quote (Psalm 23:4).