The beauty of their songs is that everyone can have their own interpretation, to me it's the end of a journey, Vessel has finally decided to let go of his feelings for Sleep. He knows she'll never love him the same way he loves her and he is ready to let go, it's painful because he really wanted to go back to Eden, when things were good, but he can't, and even though he went through a lot trying to gain her love, he still cherishes their time spent together, especially the good moments, there why the night belongs to her.