Hi!

[Linux.Blue]

hello and welcome to the forums and games. I'm not sure what info you heard; so I'll start from the beginning.
Penumbra was originally going to be a trilogy, but it dropped to two episodes.
However, quite recently (day or two? three?), they are I believe going to make an expansion pack from the sequel.

You can browse around, look at the topics, get an idea on what happened and will in time.

Once again, welcome!