Welcome to the forum!
Everything you are seeing on that coin is post mint damage. (PMD)
Thats what I thought but how does it get under the lettering?
If you are talking about the big bubble that got flattened it was most likely done with very high heat like a torch.
Clad quarters have a solid copper core sandwiched between 75% copper 25% nickel outer layers. Exposure to high heat can cause The layers to separate and leave a bubble.
yeah someone got board and messed with a quarter it seems