A ticking masterpiece of gears, springs, copper, and brass: The time machine lets you travel to the future and into the past, but only in 33-year increments.
When the machine is activated, a spherical wormhole forms, linking different time periods for a few moments.
The clockmaker's masterpiece
After multiple visits from the Stranger in 1986, the clockmaker finally understands what it is that he's created. He can activate the machine using a smartphone that Ulrich Nielsen left in his workshop 33 years ago and a radioactive Caesium isotope that the Stranger brought with him from the future.
The Stranger's machine
Are there other time machines out there? The Stranger brings his own model to the clockmaker for repair. It looks like an exact copy of the machine, but it's much more worn.
The Stranger isn't just using the machine to travel through time. He also wants to use it to close the passage in the caves that Mikkel and Ulrich Nielsen, among others, have used to time travel. He successfully closes the passage, but in doing so, creates a temporary rift in time.