In the last episode Lucifer is trying to figure out a way to get rid of Cain's curse so he can give God the middle finger by undoing his work.
Problem is he just can't figure it out... until Chloe gives him an idea... go back to when Cain killed his brother and prevent it from happening.
Hmm, can Lucifer time travel?
What would be the long term ramifications of the first murder not happening?
Kind of interesting.