ONI Acrisius

ONI Acrisius (hull classification symbol: IX-455) is a state-of-the-art, special purpose used by the Office of Naval Intelligence's Watershed Division.

Service history
Acrisius was assigned to Argent Moon by the Office of Naval Intelligence as a support for ONI's exfiltration protocol where the prowler could be activated for swift departure, in the event that high-profile ONI personnel aboard Argent Moon were in danger and needed to evacuate the ship. However, as the ship's personnel were quickly killed in a bioweapon incident in 2557, Acrisius was never used for this purpose.

When Argent Moon became occupied by forces from Jul 'Mdama's Covenant in 2558, Spartan-II Blue Team was sent to reclaim the vessel. However, when a Covenant fleet exited slipspace around Argent Moon, Blue Team moved to scuttling the ship to deny the Covenant the asset. After setting the vessel's reactors to overload and detonate, Blue Team fled to the ship's hangar bay and boarded Acrisius as they couldn't reach their own Pelican to escape. Piloting the prowler out of the vessel, Blue Team barely escaped the destruction of Argent Moon. Rather than return to, Blue Team decided to travel to the human Outer Colony of Meridian to investigate Cortana's apparent survival. After activating Acrisius's active camouflage to avoid the Covenant fleet, the prowler entered slipspace for Meridian. Blue Team landed the Acrisius at Apogee Station and entered the nearby mines in search of Cortana, abandoning the ship.

After Blue Team went AWOL, Fireteam Osiris was dispatched to Meridian in search of them. After arriving at Meridian Station and interviewing the miners, Osiris learned of a UNSC ship headed to Apogee Station which had come under attack and correctly guessed that it was the Prowler. Governor Sloan agreed to transport the team to Apogee Station where they discovered the abandoned Acrisius surrounded by Prometheans. After clearing out the enemies, Osiris boarded the Prowler and accessed its logs. In the Acrisius databanks, Osiris found a map of Apogee Station pointing to the path Blue Team took into the nearby mines, and Osiris followed Blue Team's path. The Acrisius was abandoned at Apogee Station by both teams, with Blue Team departing with the Guardian and Fireteam Osiris returning to their Pelican on Pinnacle Station.

Unknown to the Blue Team, the ancilla Intrepid Eye also managed to barely escape Argent Moon by attaching herself to the ship.

Trivia
The ship was named after Acrisius, the mythical king of Argos, who was accidentally killed by the demigod Perseus, a possible reference to the incident that accidentally killed the crew of Argent Moon.

List of appearances

 * Halo 5: Guardians
 * Limited Edition dossiers
 * Halo: Divine Wind