Title text:
It's ok if you want to close close your eyes for the slab graveyard, so you can still have fun riding the mantle plume back up afterward!
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3303/
You can check out the explainxkcd link in the post. That site has explanations for all the xkcd comics