Good selection, especially as a primer into his works. I assume he is new to you, and if so, here's some brief background that you might not get initially on a video. He was a PhD in Hebrew and was always fascinated with UFOs and related genre. He used to appear often on the radio show Coast to Coast AM and talk on ancient alien stuff. He debunked Sitchin and errant theologies a lot, so the Bible Code Myth is a standalone book. But before Angels, you should read Supernatural. It's a primer on the Deuteronomy 32 worldview aka the Divine Council Worldview. That's really what Heiser is noted for.