If you haven't watched God's Muslim Warriors (Part 1), you should watch it - watch all 11 parts. I learned a lot from watching this. I did not know about Hizb al Tahrir before watching this.
Parts of the documentary are downright scary. Other parts I found to be quite funny. I wanted to but cannot embed Part 7, which I found to be absolutely hilarious. For the record, I do not believe that the Hidden Imam will return and usher in a new era of peace and Islamic justice, and that there might be conflict with Jews and Christians, at which time Jesus will be sent to mediate!