The most common and most likely answer to this crossword clue is the 8 letter word VOLCANOS
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Buddy explains!

The straight part
We know that "They might explode" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case they might explode = volcanos.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does VOLCANOS mean?
VOLCANOS noun- A vent or fissure on the surface of a planet (usually in a mountainous form) with a magma chamber attached to the mantle of a planet or moon, periodically erupting forth lava and volcanic gases onto the surface.
- A form of firework.