The last vignweek prompt was a theme mashup. I brainstormed for a while, wanted to have a really solid concept, and the idea of Power Miners breaking through into some kind of underground cavern seemed like a good one. Batman was a logical choice, though I don't have any Batman minifigures. I've always loved the Power Miners Thunder Driller and it was great to recreate at a slightly smaller size. The Batcave was also a fun challenge!