Several points about this particular strip:

1. After #103 I wanted to bring Colonel Haken back to life again, rather than just have him strangely reappear with no explanation. It's only a semblance of continuity, but I cling to it like a man committed to an Arkham asylum clings to his last remaining shreds of sanity...
2. Yeah, that's meant to be Hitler's disembodied brain. I hope that's obvious enough. If not, that's what this annotation is for!
3. Why is Hitler's brain disembodied, you ask? Because it seemed a good idea to throw in the classic gaming-geek-culture reference to Hitler's Brain. (And Lego don't make Hitler minifigures, for obvious reasons, but they do make a nifty brain-in-a-jar piece.)
4. "But this is set in the 1930s! Hitler's still alive!" A guy has just been brought back to life after dying because he picked the wrong cup as the Holy Grail, and you're worried about historical accuracy?
5. This is only the second time I've ever had to bend a speech bubble arrow. #92 was the first.