WT looks like an oversized wooden lock with three gears (well, two and a half) on its front, one with a large chunk bit off, the result of Little Johnny’s ill-fated attempt to open the lock (so we are told in WT’s narrative, a story of 19th century settlers who come across a mysterious chest you need to help open). Other than a small hole on the right side, there is nothing else to work with: one of the smaller gears spins freely while the other two are locked in place, separated from the spinning gear by a few mm gap.

WT has a lot more going on under the hood than I had initially suspected: the linear solve has a good rhythm, as I kept experimenting with what else might be possible, a surprising number of possibilities arising as the solve progressed. The solution relies on discrete steps, allowing you to clearly know when progress has been made, somehow avoiding blind tricks even when so much is hidden. It is a good example of how sequential discovery puzzles guide you along a journey through its various stages, various tools provided as you progress, steps and sections leading you along to the next.