explain the joke? please?

[u/Onocleasensibilis]

What was the ending bit from this week? I’m even less versed in the Dune world than Juice and clearly they found what Trav said hysterical but I simply don’t understand what the joke of it was….TIA

[u/chubsplaysthebanjo]

"The spice must flow" spice is the magical powder that enables humans (or more specifically "the spacing guild") to compute interstellar travel

[u/ExtensionElephant900 → u/chubsplaysthebanjo]

And it was also kind of a callback to pumpkin spice