Operation A: Orphic Spear
From Halopedia, the Halo wiki
Operation A: Orphic Spear is the first operation of Halo: Spartan Strike. This operation is an in-universe simulation of an event that took place during the Battle of Mombasa in 2552, and follows a team of Orbital Drop Shock Troopers on a mission to recover the Conduit; the ODSTs are replaced by a Spartan during the simulation of the operation.[1]
Missions
Transcript
{Cutscene}
Greetings Spartan! I'm Roland, the UNSC Infinity's AI. The Office of Naval Intelligence has cleared you to access a highly classified combat simulation.
It's based on events that took place during the Battle of New Mombasa in 2552.
Six years ago, a Covenant fleet attacked the city of New Mombasa. Any school kid can tell you that much. But many details of that attack were known only at the highest levels of government... Until now.
While fighting raged throughout the city, Covenant forces secretly hunted for the portal to the Ark. But they were also looking for something else... The operation we'll study today began when we learned the Covenant found an artifact known as the Conduit. Back in 'fifty-two, we sent a team of ODSTs in to secure the artifact. Out combat simulation is up and running, so let's see how you do playing through this operation as a lone Spartan. Good luck!