Halo Alpha
Halo Alpha

This article is about the level. For the super carrier, see UNSC Infinity
and for other uses, see Infinity (disambiguation).

Infinity is the fourth campaign level of Halo 4.


The level starts off with a cutscene of John-117 observing the UNSC Infinity lose control and crash in the jungle. He proceeds to fight his way through Promethean forces to reach a Forerunner structure, where he reunites with Lasky and the Spartan-IV Sarah Palmer. Along with a few marines, John clears out a landing zone for a Pelican to extract them. He discovers Jul 'Mdama's Covenant have allied themselves with the Prometheans. John and a detachment of Spartan-IVs land near the Infinity, where they use a Scorpion and a Warthog to fight through Covenant forces, reaching the Infinity. John-117 then utilizes a Mantis to clear out Covenant and Promethean soldiers to reach the weapon controls for the Infinity. After clearing off several waves of Covenant Phantom dropships, he activates the weapons for the Infinity, firing at the Didact's Ship and causing him to retreat.



Scene opens on a jungle and pans down to Chief.

  • Cortana: "Stay low; recon sortie heading this way."

Phantoms and Banshees fly overhead of John's position.

Camera changes angle to show the Didact is scanning the crashed Infinity. Several Covenant ships also converge upon the crashsite.

  • Cortana: "The ship looks intact."
  • John-117: "Something tells me that's only because the Didact wanted it that way."
  • Lasky: "This is Lasky to UNSC Infinity. We're up to our necks in bad guys down here. Does anyone read?"
  • John-117: "This is Sierra 117 of the UNSC Forward Unto Dawn. We're on station, ready to assist."
  • Lasky: "Negative copy, sounded like you said 'Forward Unto Dawn'? Come again-"
  • Cortana: "Signal's bouncing in and out; I can't clean it up."
  • John-117: "Light up their friend-or-foe tags; we're gonna need something to zero in on."



Four Banshees and three Phantoms fly toward Infinity

  • Cortana: "I'm seeing multiple IFF tags below the tree line. Painting the closest one on your HUD."

Chief makes his way down through the fog-laden jungle.

  • Andrew Del Rio : "Infinity to Commander Lasky. We've lost contact with your Pelicans! Report in!"
  • John-117: "They must not have received his distress call."

John finds a clearing with several Promethean Knights , but they teleport away before engaging. A squad of dead Marines is left in their wake.

  • John-117: "Lasky?"
  • Cortana: "One of them's an officer. Check his IFF tag."

John examines the IFF tag.

  • Cortana: "The tag I.D.s him as Jimenez, Paolo J."
  • John-117: "Then Lasky's still out there somewhere."

John listens to the recording from the Marine's recorder chip.

  • Marine (recording): "I mean c'mon Sarge. Who sends recon downrange in the middle of a firefight?"
  • Marine (recording): "What was that?"
  • Marine (recording): "Tangos on our six!"
  • Marine (recording): "Now they're be-AAAA!"

The transmission falls silent after some gunfire. John-117 then continues to trudge through the jungle, but stumbles upon some Crawlers and Knights. John eliminates any hostiles in his way before coming to a small ledge where a Knight has just stabbed a Marine with its blade arm. The Marine detonates a grenade as he dies, killing the Knight.

  • Cortana: "Hold up, what was that he dropped on the ground over there?"

John examines the object in question. Upon activating it, Cortana chimes in.

  • Cortana: "This is what they've been using to see through the fog."

Nearly a dozen enemies are lit up on John's HUD. John clears the area and proceeds.

  • Cortana: "We've got another IFF on the far side of this thicket."

John makes his way forward and finds a dead Marine with his IFF tag. John examines the IFF tag and a transmission from Lasky and company is played back.

  • Lasky (recording): "We should get eyes out there looking for the others."
  • Palmer (recording): "Peters, you heard Commander Lasky."
  • CPO Peters (recording): "CFB, ma'am. Bulldogs! On me! We're going for a walk."

Transmission ends.

  • Cortana: "Lasky's been through here, recently by the timestamp."

John continues through the jungle, encountering resistance as he goes.

  • Cortana: "I've got another IFF tag, but as far as I can tell we're moving into a choke point. This may end up as a dead end."

After clearing a group of Crawlers and ascending some convenient tree limbs, John reaches a small Forerunner structure with a sealed door. The IFF tag is on the ground along with crates of UNSC equipment and weapons.

  • Cortana: "That's the friend-or-foe tag, but where's whoever it belongs to?"

John examines the IFF tag and a transmission from Lasky and company is played back.

  • Marine (recording): "XO. We got it!"
  • Palmer (recording): "MOVE! MOVE! MOVE!"
  • Marine (recording): "Light's green!"
  • Marine (recording): "C'mon. Crank it!"
  • Lasky (recording): "Palmer, get your folks inside!"
  • Palmer (recording): "Yes sir! FOURS! Go!"

Transmission ends.

Suddenly, several IFF signals appear on Chief's HUD; just on the other side of the door.

  • Cortana: "Multiple I.D.s. Chief, they're friendlies!"


The door to the small Forerunner structure opens and John-117 is revealed to the Marines that barricaded themselves inside. Three Spartan-IVs emerge and survey the area. Lasky approaches John.

  • Lasky: "Afraid we're gonna have to give you an IOU on that welcome home party."

Lasky extends a hand to John, and they shake hands.

  • Lasky: "Tom Lasky, First Officer of the Infinity. Never though I'd see you again."

Camera focuses upon an unmasked Commander Palmer giving orders to the Spartan-IVs.

  • Palmer: "Seal 'er up."

Palmer saunters over to John with a look disbelief and amusement. She levels him up.

  • Palmer: "I thought you'd be taller."

A radio transmission cuts John and Palmer's encounter short. John, Lasky and Palmer divert their attention to the Marine with the operable radio.

  • Del Rio: "…ground forces are ordered to return to Infinity immediately."
  • Marine: "Commander! Radio's hot!"

The door closes and the trio, along with the rest of the Spartan-IVs gather around the radio.

  • Del Rio: "…respond to Comm… on what frequency? What frequency, dammit!"
  • Lasky: "Infinity, this is Commander Lasky. Pelican recon teams are down. Repeat. All birds are down. We've got numerous causalities and require immediate assistance. Over."
  • Del Rio: "Finally… Did you get the coordinates to that gravity well."
  • Lasky: "Affirmative, sir. But we're gonna need a bus out of here."
  • Del Rio: "Make it happen!"

Del Rio signs off. Lasky is visibly dismayed by the situation and Del Rio's lack of support.

  • Cortana: "You were sent on a scouting run in the middle of an attack on the ship?"
  • Lasky: "The Captain thought Infinity could provide us cover and hold off the attack at the same time."

Palmer approaches Lasky.

  • Palmer: "Sir, we'll never get the wounded back to the ship on foot."

Lasky silently agrees, but he quickly formulates a plan. Lasky approaches John-117.

  • Lasky: "I don't know if it's too soon to ask you for a favor but we're going to run out of breathing room here real quick. I don't suppose you're any good at clearing LZs?"
  • John-117: "On occasion. I'll send out an all-clear once the area's secured."



John, and two Marines emerge from the small Forerunner structure.

  • Cortana: "A topographical scan of the area shows a break in the foliage north of here. Should be big enough to bring in a dropship for evac."

Enemies are immediately upon John and the Marines, but the group makes quick work of the hostiles. John passes a UNSC radio on the ground. Marines, gunfire and screaming can be heard through the transmission.

  • Marine: "Pull back! The ship is being overrun!"
  • Marine: "This ship's as big as a city. How's it being overrun?"

John and the Marines press forward.

  • Lasky: "Chief, it's Lasky. We're getting reports of friendlies pinned down near your position. Can you assist?
  • Cortana: "Commander, this is Cortana. We're on our way."

John finds the four Marines engaged with a large group of Promethean hostiles. Upon approaching many of the Marines will comment in disbelief.

  • Marine: "I though he was dead."
  • Marine: "Holy mother of…"
  • Marine: "Who's that?
  • Marine: "What. The. What?"

Crawlers, Watchers and Knights, as well as two turrets, now block the passage between the Marines and the path to the LZ.

  • Cortana: "Turrets! Find some cover!"

John-117 and the Marines clear the area and approach a sealed door. UNSC turrets and weapons are scattered along the hilltop.

  • Cortana: "The Marines got trapped trying to get through these doors. Look for an interface."

Chief removes Cortana and inserts her into the pedestal near the entrance.

  • Cortana: "These doors open into a cave system with space large enough for an LZ. Hold them off long enough for me to open the doors!"

John-117 and the Marines repel a wave or two of Prometheans.

  • John-117: "Cortana? How close are we?"
  • Cortana (rampant): "YOU DO YOUR JOB AND I'LL DO MINE, OK?"

Eventually all the enemies are cleared.

  • Cortana: "Got it! Passageway's unlocked. Come and get me!""

John retrieves Cortana from the interface. The door opens into a cave. As John pushes through, there is distortion in his HUD.

  • Cortana: "I'm sorry about back there. That hatch's security was more difficult than I expected."
  • John-117: "It's alright."
  • Cortana (distorted): "It's not alright. Nothing about it is alright."

John proceeds down the cave system. Suddenly, a Knight appears at the opening on the far end of the tunnel. The Knight appears to be ordering a small group of Unggoy.

  • Cortana: "Knight! Wait, what's he doing?"
  • John-117: "Covenant?"
  • Cortana: "They're working with the Prometheans?"

Chief enters the clearing and begins eliminating both Promethean and Covenant enemies.

  • Cortana: "I'm shocked how quickly the Didact has unified these Covenant!"

A Covenant Phantom sends in more troops and Knights teleport to the assault.

  • Cortana: "Knights!"

John eventually clears the LZ.

  • Cortana: "Cortana to Lasky. LZ is secured."
  • Lasky: "Roger that Cortana. I'll get you the coordinates for the-"

An emergency transmission from Infinity interrupts.

  • Del Rio: "Mayday, mayday. Code Red! Hostile elements attempting to gain entrance to the Infinity bridge."
  • Officer: "They're outside the hatch!"
  • Officer: "Doors breached! Doors breached!"
  • Del Rio: "All units return to Infinity immediately. That's an order!"
  • Lasky: "Chief, I'm redirecting the Spartan-IVs to rally point Alpha Sierra Foxtrot. Until we catch up, you have tactical command of the forward assault force! Rendezvous with those men and take back that ship!"
  • John-117: "Yes, sir."
  • Lasky: "Good luck Chief. Lasky out."

As John boards the Pelican, scene fades to black.

  • Pilot: "This is Pelican Five Nine Five. We have the Chief onboard and are outbound for rally point Alpha Sierra Foxtrot."

Gameplay continues as the Pelican drops John-117 at the rally point. A large group of Marines are pushing towards Infinity. John is spearheading the effort.

The Gun Show[]

  • Cortana: "Weapons free, Chief! Let 'em have it!"

The path to Infinity consists of large expanses under the jungle canopy. A Scorpion tank is available to make the final push.

  • Cortana: "We're good to go Chief. Let's show these Spartans how it's done."
  • Spartan: "Ground teams be advised. John-117 is on the ground. Advancing."
  • Lasky: "117, Lasky. We're touching down just north of your position. Proceed to starboard hangar 2-19, and we'll link up with you there."

John-117 and fellow Spartans make their way to the hangar, encountering resistance from Wraiths, Ghosts and dug-in Covenant infantry.

  • Cortana: "Commander, the hangar bay doors are sealed tight."
  • Lasky: "Roger, Cortana. We'll find a way inside and free up one of the mooring platforms. XO out."

John navigates the vehicle onto a lift and enters the hangar bay. Covenant forces have overrun the area, including a Hunter pair.

  • Lasky: "Secure the bay and I'll release the lockdown into the ship."

John-117 clears the remaining Covenant from the hangar. Captain Del Rio contacts John via radio.

  • Del Rio: "John-117, this is Captain Del Rio. Lasky just radioed. Chief, you picked a helluva time to rejoin us."
  • John-117: "Sir, what's our status?"
  • Del Rio: "That satellite took down the ship's defenses and is extracting data from the ship's mainframes as we speak."
  • John-117: "Can we break the connection?"
  • Del Rio: "Main point of contact's on the ship's upper hull. The fastest route is through the maintenance causeway. There's a Mantis docked inside the door. Take it. You'll need the extra firepower."

John-117 exits the hangar and proceeds to activate and enter the Mantis.

Shining Armor[]

  • System: "Warning: Operation of Mantis Armored Defense System prohibited without prior approval."
  • Cortana: "The hatch to the maintenance causeway is jammed. Let's do something about it."

John activates the weapons systems and destroys the door to the maintenance causeway. Promethean and Covenant forces line the corridor, but John-117 pushes through.

  • Cortana: "The Captain said the Didact's linked from the outer deck. That's where we want to be."

Several Promethean Knights and Unggoy equipped with Fuel Rod Cannons block the path between John and the lift at the end of the causeway.


John-117 terminates all hostiles and boards the lift.

  • Lasky: "Chief, it's Lasky Come in!"
  • John-117: "Go, Commander."
  • Lasky: "We've identified several Covenant jamming devices on the outer hull."
  • Cortana: "That might be how they're blocking the Infinity's defenses."
  • Lasky: "Exactly what we were thinking. Neutralize them so we can get our guns back online and show that satellite we're more than just a big paperweight."
  • Cortana: "We're on it, Commander. Cortana out."

John exits the lift in the Mantis. A short hallway opens to the outer hull upon which the MAC cannons are currently inoperable. Three Covenant jamming devices along with Covenant defenses patrol the outer hull. In the distance, several Covenant CRS-class light cruisers and the Didact's satellite survey Infinity's crashsite.

Eviction Proceedings[]

  • Cortana: "I see the jammers. Three of them. Shoot them down."

Chief destroys the first jammer.

  • Cortana: "First jammer disabled!"

The second jammer is destroyed.

  • Cortana: "That's two!"

John manages to disable all three jammers and the AA guns begin to fire upon the Covenant.

  • Cortana: "That's it. Jammers neutralized."

More Covenant forces are deployed by incoming Phantoms, and Banshees provide Covenant air support.

  • Del Rio: "Del Rio to John-117. The rate that thing's searching our systems just doubled! I think it knows what you're up to."
  • Cortana: "The Didact's not letting go without a fight. Hold them off! Just a few more minutes."

John-117 secures the outer hull and the Infinity's defenses begins to repel the Covenant cruisers.

  • Cortana: "That's how it's done."
  • Del Rio: "Captain Del Rio to Sierra 117. The MAC network's reading operational but our EM relays are malfunctioning. You'll have to initiate the link manually."

John manually activates the MAC cannon firing sequence.

  • Cortana: "That's it. MAC controls restored!"
  • Del Rio: "Forward MAC batteries, get that damn orb away from my ship. All cannons. Fire at will."

The combined fire draws the Didact's satellite away from the Infinity.

  • Cortana: "It's working. The Didact's retreating!"
  • Del Rio: "Del Rio to Infinity All Hands. We are Condition Yellow. Stand down. Section heads report in, begin damage assessment."


Infinity is seen leaving Requiem's surface. Scene transitions to Captain Andrew Del Rio on the bridge with John-117, Cortana and Lasky.

  • Del Rio: "What I want to know, people, is: Where the hell did those things come from?"

A hologram depicting a Promethean Knight is displayed on the holodeck.

  • Cortana: "It's possible that they're native to Requiem... or whatever counts as native for a Forerunner AI.
  • Del Rio: "We've never seen this type of offensive reaction from any of the other installations."
  • John-117: "Other installations?"
  • Del Rio: "Mr. Lasky."

Lasky displays a holographic image of one of the remaining Halo rings and a base constructed in the asteroid field.

  • Lasky: "Infinity's mission has been to locate the remaining Halo rings, and establish permanent bases to study them for decommission. We've got locations up-and-running around Installations 5 and 3, but lately they've run into some setbacks."
  • Del Rio: "A science team got zapped excavating a Forerunner artifact. This sensor data is all that was left."

A wealth of concentrically-aligned Forerunner glyphs are display holographically.

  • Cortana: "Interesting... These symbols are a derivation of the Forerunner glyph system.
  • Del Rio: "And our geeks managed to pull some coordinates. I'll give you three guesses where it led."

Palmer cuts-in and hands a datapad to Del Rio.

  • Palmer: "Sir, Gypsy Company is prepped and ready to roll, on your orders."
  • Del Rio: "Thank you, Palmer. Mr. Lasky, you take point. I want boots on the ground in sixty."
  • John-117: "Captain?"

Del Rio is clearly off-put by John's questioning tone.

  • Del Rio: "This is a first contact scenario, John-117. Priority is to free Infinity from Requiem's gravity well and file a threat assessment back at FLEETCOM."
  • Cortana: "You mean we're leaving?"
  • John-117: "Sir. Infinity drove the Didact back. He's vulnerable."
  • Del Rio: "He isn't the only one. You know I'd think you, of all people, would appreciate the benefit of living to fight another day."

Del Rio walks away. Chief and Cortana simply stare at each other in silence, perhaps quietly condemning their current predicament. Scene fades to black.


Icon Name Description Value
H4Achievement04 Infinity Complete the level on Normal or higher. 10G
H4Achievement21 Bros to the Close Complete the level without a single preventable Marine death on Heroic or higher. 20G (H4), 10G (MCC)


  • Jul 'Mdama's Covenant and the Prometheans work together for the first time in the game on this level.
  • It is odd that the E3 2012 gameplay demo made this level seem like the first encounter with Prometheans despite the demo at the European Gaming Expo showing Chief fighting them in the previous level.
    • 343 may just have thought it was easier to introduce the UNSC Infinity and the Prometheans in the same level just for the demo.
  • If one were to stay and watch the Phantoms and Banshees in the beginning, they would see the group of seven stop in front of a hill.
  • This is the first campaign level in which the Mantis is found.
  • This mission marks the first time John-117 has met another Spartan in five years and is the first in any Halo game.
  • The Spartan-IVs in this level seem to respect John-117 more than normal Marines.  
  • There are several buttons around the inside of the Infinity that upon activation, a voice will notify the reason why the player cannot enter. One of these responses includes "Access denied. Huragok population reserves accepts absolutely no personnel during category three emergency states and higher," implying that the UNSC has adopted Huragok into its ships for repair work and possibly even technology advancement.
  • At the beginning when you find the last of the IFF tags, if you use Promethean Vision you will see behind the sealed door 4 Spartan-IVs.
  • During the section in the forest where you are aided by Marines, a good tactic is to give them LightRifles, which makes them both more useful and less likely to die. This is especially helpful in getting the Bros to the Close achievement.