**Halo 4 Spartan Ops: following Halsey's signal through Key**

**Halo 4 Spartan Ops: following Halsey's signal through Key** **MCC guide. Episode 9 spoilers.** Key moves between signal tracing, a Scorpion assault and a long fight through Lockup. Science Mountain is the chapter where the route can be particularly misleading: you get a tank, lose access to the tank route, then receive another tank later. Trying to force the first Scorpion through the footpath is wasted effort. **1. The Search for Halsey** Clear the Covenant at Cyclone and enter the marked building. Defeat the Hunters and Elites inside, then access the communications terminal. Follow the next objective across the facility toward the power disturbance. Deal with the Promethean ambush before entering the power-source structure. Investigate the console and hold against the attack while the signal is analyzed. Friendly defenses join the battle. Once the defense ends and the objective updates, activate the terminal and follow the route to extraction. The ramp into the power-source building gives you a recognizable place to fall back toward, but don't let it become a position you refuse to leave. If enemies close in from several angles, move while your shields still give you that option. During the defense, destroyed friendly beam turrets can be restored at marked controls. I'd only do that when the approach is clear. Trading your life for a turret that immediately gets overwhelmed doesn't improve the situation, especially when ranged Crawlers are covering the controls. **2. Clean Up** This is the Episode 9 chapter at Control, not the earlier Episode 2 chapter with the same name. Clear the opening Covenant force, then activate the first communications terminal. Roland directs you to a second and then a third as he traces the signal. Hold off the Prometheans while he finishes his work. When Miller marks a safe position for the airstrike, move there and let the strike clear the remaining attackers. Don't turn the ending into a last-enemy hunt in the strike area. The objective has changed from holding your ground to getting clear. The opening puts heavy enemies close enough that finding a useful weapon quickly matters. A rocket launcher is available near a pillar by the Marines' position, and nearby Covenant supplies offer alternatives. Use heavy ammunition on the Hunters rather than spending it on an exposed turret gunner you can remove with a precision shot. As you move between terminals, avoid leaving your only retreat route full of enemies. Secure enough ground to reach the next control and enough behind it to recover if the next wave arrives faster than expected. **3. Science Mountain** Board a Scorpion and advance through the valley. At the first shield, clear the attackers and use the marked control so Roland can weaken the barrier. **Then shoot the shield** to bring it down. At the next blocked route, finish the ambush and follow Miller's marked side path **on foot**. Clear the area beyond it and work uphill through the pass. Secure the next landing area to receive replacement Scorpions. Operate the shield controls, board a new tank and destroy the weakened barriers through the cave route. Beyond the tunnel, clear the Covenant and Prometheans around the destination and activate the communications terminal to finish. The two-step shield procedure is the part to remember. Using a control makes the shield vulnerable; it doesn't necessarily remove it. Firing at a barrier before the required interaction also won't advance the sequence. Keep the tank's next few meters clear before looking for a distant target. A powerful cannon doesn't help much if you've driven past infantry that can attack from behind while you focus uphill. When the tank drop arrives, stay out from underneath the delivery area so the Pelicans can put it down. **4. Revenge** Use the opening Warthogs and allied Marines to clear the first area of Lockup. Hold through the reinforcement waves, including the Hunters. Once the doors open and Ghosts emerge, defeat them and move into the next section. Secure that area, then investigate the marked Marine signals. The investigation leads into another ambush. Fight through the successive Covenant reinforcements, including Wraiths and Hunters, until the chapter ends with more attackers approaching. That ending leads directly into The Hammer. Don't expect the rescue-and-extraction pattern from earlier episodes to repeat here. If you're using a Warthog, resist the temptation to drive into every freshly opened doorway immediately. Let the Ghosts emerge into ground where you can maneuver, deal with them, then move through. In tight spaces, getting the gunner a stable line of fire is usually more useful than trying to run over every Elite. On foot, keep an anti-vehicle option available through the later defense. A weapon that handled the infantry comfortably may leave you badly equipped when the next Wraith arrives. **5. The Hammer** Survive the opening attack, then move through the opened doors to assist Poker Squad. Clear their attackers and follow the new objective toward Hawk Squad's signals. Work through the Prometheans and activate the marked control to open the light-bridge route to the gravity lift. Ride up and investigate Hawk's tags. Activate the first marked panel, defeat the incoming attackers, then repeat the process at the second. After the final enemies are gone, activate the last panel to complete the device and finish the episode. There are three device panels in that final sequence. Treat each interaction as preparation for another fight: reload first, locate your cover and keep a weapon suited to Watchers ready. Running straight to the next control while still recovering from the previous wave gives the new attackers an easy opening. Hawk's signals aren't surviving Marines waiting for an escort. Follow the investigation and device objectives rather than searching for characters to lead out of the room. **Before moving on** Check off all five chapter completions separately. The episode ends after The Hammer reveals the map, not after the first successful signal trace. If you're working toward solo Legendary completion, preserve that distinction in your checklist; the two chapters named Clean Up are separate entries in different episodes.