Octanitrocubane

Octanitrocubane, also known as octas, is a shaped high-yield explosive used by the United Nations Space Command that has a yield equivalent to one hundred kilotons.

Description
Octas are tubs of high-yield explosive that costs more than a HAVOK tactical nuclear weapon to produce. Despite this, they are considered worth making as they are shaped charges and their explosive yield does not decrease in a vacuum. Octas have a yield equivalent to one hundred kilotons and run on timed fuses. Additionally, octas have a sixty-minute automatic countdown that can be activated. This acts as a failsafe in case the person carrying the octa is killed or the octa falls into enemy hands. If an override code is not entered before the countdown ends, the octa will detonate on its own.

History
In April 2526, during Operation: SILENT STORM, the SPARTAN-II's and Black Daggers armed themselves with octas alongside HAVOK tactical nuclear weapons for an attack on the Covenant planet of Zhoist and the Ring of Mighty Abundance. During the mission, the Spartans and Black Daggers of Blue and Green Teams planted octas throughout the facilities of the Ring they passed through, destroying each facility.

During the battle, eight of Green Team's Black Daggers were picked up by ships of the Fleet of Inexorable Obedience. The Black Daggers managed to sneak their octas onboard with them when they were captured, running on the sixty minute automatic countdown and as a result, only laughed in the faces of their captors when interrogated. When the timer ran out, the eight octas detonated, destroying six Covenant ships to the astonishment of the watching UNSC forces from their hidden Prowlers who realized what the Black Daggers must've done even after being defeated.

List of appearances

 * Halo: Silent Storm