Check out my latest Halo 5 forge map, Dr. Tim’s Time Machine.
It involves time travel and building a mysterious device.
There’s much more info, and pictures, on my forgehub post:
http://www.forgehub.com/maps/dr-tims-time-machine.1397/
Let me know if you want a hint or have any questions about the scripting used (there’s a ton of it).