What do you mean that's not what we're reading?!?
Chol HaMoed means “The Non-Holy Appointed Time”. Chol (“Non-Holy”) is opposite from “Kodesh” (“Holy”); and Ha-Moed simply means “the appointed time”.
When a holiday lasts longer than a day or two (like Sukkot or Pesach), the days at the beginning and end are usually “chags” (no work, have a big hoopdie-doo, etc) and the days in the middle are more or less business as usual. Chol HaMoed. Non-Holy twiddle your thumbs waiting for the next chag days.
The problem with Chol Hamoed is that it’s still in the MIDDLE of a holiday, so it’s still special. Especially when it comes to Torah readings.
If Shabbat falls *on* a holiday (or the start or end of a long holiday like Sukkot), it’s pretty easy to understand why we’d put the regularly scheduled Torah reading on pause (don’t worry, we set the DVR to record the episode so we can play it the following week) and read something festive and special. But if Shabbat hits in the middle of a long holiday, there are STILL special reading And they are different than the special readings you would have if Shabbat and the start/end of the holiday coincided.
Obviously the next question is “how the heck do I know what to read then?!?” And I have two answers:
1) CYLR (Consult Your Local Rabbi)
And may the Force be with you.