The UNSC Infinity one of the most important UNSC ships, you were assigned to this ship after your hard-working in other missions as a spartan (decide if you have a team or you're a lone wolf), you're currently in one of earth bases resting when a marine calls you informing the pelican has arrived to take you to the UNSC Infinity that's currently in the space close to earth patrolling

As expected once you're there you will meet captain lasky and other Spartans so good luck!