It looks like you have a lot of unnecessary formatting in the inner HTML. It looks like the content was formatted in a Word document, and there are likely styles generated in Word that are causing issues in Internet Explorer. Can you do your font selection and font resizing with Hype's built-in typography tools?
You can get the plain text from the different scenes by selecting the text and pasting it into a plain text editor, then back to Hype. You can use
<br> for line breaks. Select text and press ⌘ + b to make it bold, and use the text resize controls to adjust the text size.
Is this in the Smithsonian museum?