A new mystery!

Oh gosh! I have no idea! And we won’t know for some time. What a conundrum.
Possible solutions to this mystery:
- Joker sprays acid all over the trap and/or Batgirl
- Joker shoots Batgirl
- Joker stamps so hard he cracks open the very Earth itself and falls into the gaping crevice á la Rumpelstiltskin
- Joker laughs
- Joker seethes
- Joker pretends THAT WAS HIS PLAN ALL ALONG
- It really was his plan all along
But what on Earth does “did” mean anyway?! I guess we’ll have to wait to find out what The Super Dictionary makes of this innocuous but crucial helping verb.