Osiris Suite, Act 1 is the thirty-third track included in the Halo 5: Guardians Original Soundtrack.
The first section is played during the cinematic of the level Blue Team when John-117 sees a vision of Cortana. It is also played at the beginning of Guardians when the first Guardian goes into slipspace. The second section is played during the opening cinematic of Blue Team when Fireteam Osiris returns to the UNSC Infinity. The third section is played in Guardians during the Mantis run. The end of the track can be heard at the end of Warzone matches.