This episode was intense. I don't often get edge-of-my-seat worried during Race to the Edge, partially because of the nature of the show and partially because there's a movie set after the show that assures me the main characters will live. However, sometimes things manage to be intense enough that that flies out the window.
That's how I felt watching the struggle to get the egg to the right place in the volcano before everyone was swallowed by lava. I think it was more the scenes taking place with the group outside the volcano than the scenes actually inside the volcano that I found the most intense (which might be kind of odd). Watching Astrid and Throk try to get into the volcano themselves and almost die in the process was the big kicker. For a minute at the end, I thought they might actually kill Throk off, and while that wouldn't have been a huge heartbreak, it definitely managed to affect me.
The arrangement for the egg was pretty cool too. One has to wonder how long this tradition has been going on if that elaborate thing was built and these dragons have been trained so that each generation knows what to do with that egg. I also have to wonder how it stays intact if it fills up with lava time and time again, but I guess that's something I have to try not to think about. It looked cool at least.