Starry Night is a short CG spot released on December 4, 2006 as an ad for Halo 3, and intended to be used as a television commercial.
It begins with a young boy and girl lying in grass contemplating the existence of life on other planets. Who they are and where they are is unknown and still up for debate. The boy turns to look at the girl, but instead sees John-117's helmet lying on the ground.
It suddenly transitions to the Master Chief's point of view, with the sound of the two kids screaming merging into a Wraith's mortar detonating. He is lying on the desert ground looking at his fallen helmet. The Master Chief raises his hands up—still dazed and temporarily half-deaf from being knocked out—and staggers towards his helmet (hearing the girl's voice in his head again). As soon as the helmet is put on, the camera switches to a third person view, revolving around the Chief who's crouched on the sand, recovering from the blast that sent him off his Mongoose (shown lying on its side.) Sound finally returns fully and communication from Cortana and some soldiers could be heard (refer to transcript). A MA5C Assault rifle is also shown lying on the ground. The scene switches to Master Chief getting up - now fully recovered - and holstering the rifle to his back. At this point, a few Plasma Mortars could be seen heading high up into the sky, one which is heading towards Master Chief. Quickly, he responds to the soldiers - informing them that he is not lost yet - and reaches for a Bubble Shield, activating it just in time as the Plasma Mortar reaches the vicinity, sending the Mongoose flying away. As soon as the dust clears and the Bubble Shield is down, the Chief swiftly starts running forward - at the same time arming himself with the Assault rifle, while narrowly avoiding an explosion from an unknown source. The camera then switches to tailing the Chief's back, where he is shown to be preparing to take a leap from the edge of a small cliff and drop into a battalion consisting of (or at least, shown) six Wraiths, 14 Brutes and one Brute Chieftain who (while the others run away) anticipates the Chief by raising his Gravity Hammer. The final shot shows the Chief "landing on the camera" and it cuts to a black screen with the words "Halo 3" shown.
The kids and the clumps of grass around them were taken from real footage. The CGI doesn’t begin until the Chief’s helmet is seen for the first time. As for who the kids seen at the beginning are, either Bungie or 343 Industries have yet to give a straight answer. They may or may not be John and another female Spartan. KP has confirmed that the trailer took place on Earth. However, he did not explicitly state that the children were on Earth. 
(Two kids are laying in the grass, looking up at the stars.)
Boy (John): "You ever wonder what's up there?"
Girl (Ellie): "Like what?"
Boy (John): "Maybe someone up there is wondering what it's like here."
Girl (Ellie): "I guess. Do you think we'll ever meet them?"
Boy (John): "I hope so. Don't you?" (He turns to look at the girl, but instead sees a MJOLNIR Mark VI helmet.)
(A Wraith mortar detonates nearby. The lighting changes and Master Chief wakes up. Myriad voices are heard, some in his head, others from his radio.)
Girl: "Do you think we'll ever meet them?"
(Master Chief puts on his helmet, and regains his balance.)
Cortana (faintly): "Chief, leave me!"
Marine #1 (radio): "Is anyone out there?"
Sergeant Johnson (faintly): "Chief!"
Marine #3 (radio): "Marines! Fall back now!"
Sergeant Johnson (radio): "Any sign of the Chief?"
Marine #4 (radio): "Negative, Sir. I think we lost him."
Master Chief: (looking up at incoming mortars, pulls out bubble shield ) "Not yet."
(He throws a bubble shield onto the ground, creating a shield that protects him from another Wraith mortar. Quickly, after the dust clears, he runs forward. While running he holsters his pistol and pulls out his assault rifle. He then leaps off a cliff into a pack of Brutes, and the ad ends.)
Bungie Official: "Product not yet rated."
- As the opening scene seems to be a flashback, it is possible that the two children are on Eridanus II, with the boy being John-117 and the girl being either Ellie Bloom or Parisa. In an interview with Benjamin Giraud, Ellie stated "On warm nights, sometimes our parents would let us go out to the green space and lie in the grass... and just stare up at the stars.", giving evidence that she is more likely to be the girl.
- The Marathon logo and the "on" symbol are visible on the Master Chief's Assault rifle.
- The Brute Chieftain in the trailer holds a Gravity Hammer that is identical to the Fist of Rukt.
- If looking closely, the face on the helmet seems to be a skull.
- When the Master Chief looks at his Assault rifle, a Warthog is seen in the background. However, everywhere else in the trailer, a Mongoose is seen.