Halo: Uprising Issue 4

Halo: Uprising Issue 4 was released on April 15, 2009 and is the last of four in the Halo: Uprising series of comics.

Plot synopsis
The story starts off in the Cleveland sewers with the hotel concierge Ruwan, Myras Tyla, and a squad of UNSC Marines. They eventually end up in a secret underground UNSC base. Ruwan explains to the marines how he and his brother, Colonel James Ackerson, made up the Key of Osanalan when they were boys.

The UNSC come up with a covert operation to bring the Key to Covenant command. The Key is to act as a tracking device to locate the whereabouts of top Covenant leaders, and thus stage a significant assault on the Covenant. Ruwan insists that he be the one to deliver the Key to the Covenant, by himself. When the Covenant picks him up, he declares the Key of Osanalan is, in fact, himself. The ploy works, and Ruwan is taken to the Minister of Inquisition on the cruiser Harbinger of Piety. Ruwan is still being tracked by the UNSC using a chemical tracking compound referred to as Tykos 30, allowing the MAC platform Nassau Station to lock onto his position and fire, destroying the Covenant ship he is on.

Meanwhile, John-117, having failed in his attempt to take control of the Forerunner Dreadnought's trajectory, fights his way out of the Forerunner ship's airlock in another commandeered Ghost. On the surface of the Dreadnought, he is informed that the command ship holding the "key" is to be destroyed, and that he will be within the radius of the blast unless he takes immediate evasive maneuvers. He moves to another part of the Forerunner ship to avoid being caught in the blast's wake. The Master Chief is then ordered to find a way to return to Earth quickly. His subsequent drop can be seen in the opening cutscene of Halo 3.