Brilliant Gift
From Halopedia, the Halo wiki
Summary
The Brilliant Gift is a Covenant Dropship seen crashed in the swamps in 343 Guilty Spark, later used by the Flood to board the Infinite Succor.
It is to be noted that the Flood were infected Human Combat forms armed with human weapons and NOT Covenant. They were possibly members of Captain Keyes' team when they first encountered the Flood.
The dropship crashed onto the Infinite Succor's hanger and was irreperably damaged. However, it did not matter. The Flood soon spread throughout the Infinite Succor, infecting the entire crew and the creatures in the hunting ground except the Legate. it is also good to go to the level 343 Guilty Spark and observe the drop ship your self for a better experionce.