Upon arrival the lone Covenant ship inflicted heavy damage on the Battle Group which was unable to penetrate the Covenant ship's shields. The UNSC Seattle and UNSC Thermopylae sustained only moderate damage, however the UNSC Io was heavily damaged and its Shaw-Fujikawa Translight Engine was rendered inoperable. This gave the commanding Captain the choice of whether to fall back and save the two destroyers, or fight and possibly lose all three ships. Luckily, unknown friendly reinforcements jumped in system and destroyed the Covenant ship, saving the UNSC forces. The lead ship's profile matched a thirty-year-old frigate design with major modifications, which a passive transponder identified as the UNSC Bellerophon.