: The "Cage" has been a long standing tricking challenge and dates
: back to the first few weeks of Halo 3. It is a room at the very end of
: Sierra 117. The room itself has bars around it preventing you from simply
: walking inside. After the Quid Pro Quo cutscene, drop down to the ground
: and the room is right behind you.
: Over the course of nearly 10 years, people from the tricking community have
: tried many various ideas to get inside this room, including Phantom Flip
: Launching, Phantom Turret Clipping, Phasing, trying to prevent the mission
: ending if you ride the Pelican, and more. All to no avail. We knew you had
: to find a way to go past solid geometry, but with the lack of materials,
: it made the idea of getting into this room daunting.
: Phasing near the cage seemed to be "the idea that couldn't fail"
: since when in solid space you can spawn a player back into playable space.
: However, we couldn't get close enough to the cage before we died from
: solid space to successfully spawn a player in.
: We then started to look at box launching. We had previously tried this idea
: before and while we could get our bodys in, we couldn't survive going
: through the wall without splattering, even with invincibility.
: One day, when we were messing around with box launching, we actually got sent
: into solid space alive! Turns out, we hit the edge of the cage's Arch that
: surrounds the room. When we launched, we "edge bounced" off the
: arch and it amplified our launch power just enough to send us into solid
: space. We then knew from past experience if you could place an object past
: the wall and you hit it as you launched through the wall, you would be
: able to spawn someone in the cage. We used the pelican for this purpose
: and it worked!
: HIH Cage Challenge Threads:
: http://highimpacthalo.org/forum/showthread.php?t=45370&highlight=sierra
: http://highimpacthalo.org/forum/showthread.php?t=52238&highlight=caged
: http://highimpacthalo.org/forum/showthread.php?t=45037&highlight=sierra
: (Jumprs.org was shut down in 2016 and sadly the Challenge Threads there were
: lost)

Wow!! I'll be honest - I guess I never realized that there was a gated area there. I must have missed it on every playthrough. Excellent work here, guys. Well done!