The Raid on Ivanoff Station was an attack by the Ur-Didact and his ship Mantle's Approach on the Office of Naval Intelligence research facility Ivanoff Station nearby Halo Installation 03 in July 2557. The attack was orchestrated by the Ur-Didact, who wanted to obtain the Composer, a Forerunner device that converted living beings into a digital essence, that had been moved from Installation 03 to Ivanoff Station for study. The attack was nearly thwarted by the actions of John-117 and his AI Cortana, but they were unable to stop the Ur-Didact from taking the Composer and using it on the station. All personnel within Ivanoff Station were killed, with the exception of John-117, who had been evolved by the Librarian in order to protect him from the Composer.
These events are depicted in the video game Halo 4.