One of the main mechanics of The Sojourn involves traversing through two parallel worlds; a normal, light one and a shadow version of it.
Flame[]
One can enter the shadow world temporarily by stepping into the flame, but movement drains the energy provided by it.
Shadow Gate[]
Passing through a shadow gate allows persistent stay, until another shadow gate is passed through.
Statues and Gates[]
Statues can be awakened while in the shadow world and can be used to swap places with. They also play a role in opening barred gates by placing them onto a platform that then opens the gate.
Harp[]
Harps can be used to rebuild broken bridges temporarily. The effect lasts as long as the music plays.
Relic[]
The relic can be used to activate statues and harps to enable them even while in the light world.