Charon Doesn't Make Change has the distinction of being the Marathon 2 level with the most terminals. Nine terminals in total containing eleven separate messages but only ten are readable in-game.

Charon is also where the Marathon 2 story begins in earnest. On the opening terminal we learn from Durandal about a mythical eleventh S'pht clan who left Lh'owon (system) before the Pfhor invaded and enslaved the remaining S'pht.

If this mythical eleventh clan survived,
then it has had a thousand years to grow
and learn since leaving Lh'owon. My S'pht
believe that there is a way to contact them
somewhere on the planet, and that is what
we are searching for.

The S'pht rebellion against the tyranny of
the Pfhor will certainly fail unless the
lost clan is located.

This sets the scene for the story that unfolds throughout the game.

Commenting on this level the creator Greg Kirkpatrick wrote:

This map really only ever grew into 50% of what it should have been. If you notice carefully, you'll see that right at the beginning of the level the pfhor make a run for a nearby teleporter pad. Unfortunately, if you shoot anything or if they see you (and they have eyes in the back of their heads) they turn around and come after you. In the end, it's rather difficult for them to ever get away. Otherwise, I had a lot of fun making this map, and if I'd known, I would have made it at least another 300 polygons, and you really would have felt like you were in an ancient S'pht clan's homestead.

Even without the extra 300 polygons Charon has the feel of a large level. Its layout can be initially confusing and you need to use intralevel teleport terminals to access important areas. But you are given a handy terminal image to help guide you... assuming you can read Pfhor.

Lastly, thanks to Durandal's orbital bombardment on Waterloo Waterpark this level is about to flood. Which helps to explain why these guys are in a hurry to leave at the start of the level. For more details about this see The Alien Teleporter on Charon section

A full in-game map of the level (flooded state) can be seen below.

Your mission on Charon Doesn't Make Change is to explore. Indeed Durandal spells it out for you on the first terminal. He states:

Explore the area and return here.

Oddly, this is familiar to you, as if it were from an old dream. Run around, kill stuff, run around some more, read the terminals, run some more, come back to the first terminal and see if Durandal will teleport you out.

In map-making parlance this level's Mission Type is set to Exploration and as such the player must walk on all the 'Must Be Explored' polygons to finish the level. (Note that this only applies to Marathon 2 and Marathon Infinity. In Marathon all you need to do is look at all the 'Must Be Explored' polygons to finish a level.)

There are three 'Must Be Explored' polygons on Charon and these are displayed in the map below. To make them easier to spot I have numbered them.

From a map-making perspective there is an element of redundancy here as only one 'Must Be Explored' polygon would have been necessary. Either at location 1 or 2.

Nevertheless Greg put in three 'Must Be Explored' polygons and you pass over all three as you make your way back to the start. Since the Goal of the level has now been achieved Durandal's terminal displays its second or "Finished" message and you are teleported out to the next level.

There is however another terminal on this level which also has two messages. The sixth terminal. It is located...

The in-game view shows it located between two other terminals.

The two messages associated with the sixth terminal are:

First message:

I felt S'bhuth at burning dawn

The endless war rages about us, and yet we,
the S'pht'Kr, cannot fight. S'bhuth stops
us.

He bled on me, straining. He says to not
let more S'pht feel him.

He says more will destroy him, that he was
meant not to be alone.

Second message:

We leave this message for any who might
find it, but we have barricaded off this
area, to make it difficult

S'bhuth has gone into a deep trance; we
know that we'll soon be leaving Lh'owon
but we don't know how. The border fighting
has ceased, the other clans know something
is going on, but can't see the grass for
the fires.

We have sent emmissaries to the other clans,
but only S'bhuth knows what messages they
carry.

The fact that this terminal has two messages would indicate that these are "Unfinished" and "Finished" messages yet only the second ("Finished") message will display.

The Windows 95 version of Charon Doesn't Make Change had a significant number of changes made to its design. The main ones were document by Simon Brownlee (aka Squeaky) in the Win95 Marathon 2: The Undiscovered Secrets section. One of the changes was the 'Must Be Explored' polygons. Simon wrote:

...Bungie decided to remove the 'must be explored' polys from the lower chambers of the level, leaving only one on the stairs to the first teleport terminal, and other on the window ledge overlooking the oxygen canister. The level can now be completed in 27 seconds.

You can see the two 'Must Be Explored' polygons that Simon refers to in the image below.

Even with these changes the first message on the sixth terminal of Charon will still not display.

So why does the first message not display? Greg Kirkpatrick the creator of this level is no stranger to Exploration levels and the use of 'Must Be Explored' polygons. In his early Marathon 2 level BaseDestruction he created 2 (arguably 3) terminals with secondary messages which would only display after you walked over the 'Must Be Explored' polygons. You can read about it here.

A simple mistake or something more?

Of course you can still read it on the Story page here.