OKAY.
The earlier half of the murals are a little tougher to figure out. It seems the lion and deer are two yet unintroduced characters.
It seems the orange people were having an issue with spiders (six-legged spiders). The Deer attempted to oppose the spiders on behalf of the people, but was torn apart.
The Lion put the Deer back together. The Lion also managed to come up with the Golden Spike... perhaps giving up his life in the process (note the purple lines nearby in that mural).
The Deer uses the golden spike to conquer the spiders.
However, the Deer is seemingly hurt by the spike itself. Perhaps its power is too much??
In either case, Wrip and Vinkle arrive, and for some reason take the spike and vanish with the orange people in pursuit.
Basically, that golden spike we saw in that earlier episode is... actually important, and was specifically taken away from these people by Wrip and Vinkle and hidden. Why? Dunno, but it's neat that these two have more to them than meets the eye.
As for the significance of the Golden Spike, it's likely based off the last spike of the first US transcontinental railroad, famously made of gold to commemorate the completion of the railroad.
Notably, Salem has trains, and I believe this is the first time we've seen trains in No Evil.
Perhaps this weird spider guy needs the Golden Spike to... complete something? Probably magical.
But Wrip and Vinkle took and hid it for a reason.
And considering that "pacifist McCoy girl" didn't seem too comfortable mentioning that she was from Salem...
Something smells fishy.
Either way, that movement through the whole scene was really cool.