Foster is done laughing, and is instead staring out into the horizon, his eyes fixed at the point where the Ringmaster vanished with lidded eyes and minisculely furrowed brow. He doesn't look upset, just... not very clearly anything else, either.

He lets the others scramble, but doesn't really... move. Or help.

It's only obvious he was listening after all when he finally tears himself away from his... cryptic staring to stare at the Prince Taako instead.

"... the crystal. Ask about the--the crystal, then!"

Okay, so he's not feeling very chill about this, either.